How shared-site intergenerational programs support psychosocial well-being in residential aged care: a realist evaluation

Abstract

Background and Objectives

Shared-site intergenerational programs, which co-locate services to enable interaction across generations, have gained attention for their potential to enhance psychosocial well-being in later life. However, evidence explaining how and under what conditions these programs are effective remains limited. This study examined how one of Australia’s few shared-site intergenerational programs supported older adults’ psychosocial well-being, staff experiences, and program sustainability.

Research Design and Methods

A realist evaluation was used to develop, test, and refine program theories explaining how contextual conditions interact with underlying mechanisms to generate outcomes. Data included realist interviews with residents, aged care staff, early childhood educators, and senior managers; organizational policy and procedure documents; and staff observation notes. Data were analyzed using inductive, deductive, and retroductive reasoning to develop context-mechanism-outcome configurations.

Results

Seven program theories were developed from twenty context–mechanism–outcome configurations. Psychosocial well-being was enhanced when intergenerational engagement occurred in safe and accessible environments, supported by skilled facilitation and organizational leadership, enabling participation to be experienced as meaningful and valued. These conditions activated mechanisms of belonging, reciprocity, and purpose, improving emotional well-being, social connection, and identity continuity. Staff experienced professional fulfillment and motivation when supported to facilitate quality engagement, while strong organizational culture contributed to sustainability. Outcomes varied where contextual supports were constrained.

Discussion and Implications

Shared-site intergenerational programs function as complex relational and organizational interventions. Psychosocial benefits for residents, alongside staff well-being and program sustainability, depend on alignment between facilitation practices, organizational culture, and everyday institutional conditions.

Psychosocial well-being, encompassing social connection, purpose, identity continuity, autonomy, and emotional health, is foundational to quality of life in later life (Eiroa-Orosa, 2020; Ryff, 2013). Within residential aged care homes (RACHs), also referred to as long-term care, nursing homes, or care homes, these dimensions can be constrained by institutional routines, organizational priorities, and reduced opportunities for meaningful social roles. As a result, many residents experience reduced engagement, diminished autonomy, and threats to identity and belonging, with well-documented consequences for mood, well-being, and quality of life (Australian Institute of Health and Welfare, 2024; Casey et al., 2014; Jalali et al., 2024).

In Australia and internationally, concern about psychosocial wellbeing in residential aged care has intensified in recent years, particularly in light of elevated rates of depression and anxiety among residents and growing recognition that quality care extends beyond clinical indicators alone (Amare et al., 2020; Australian Institute of Health and Welfare, 2023; Jalali et al., 2024; Royal Commission into Aged Care Quality & Safety, 2021). Residents consistently identify dignity, meaningful activity, autonomy, and social connection as core elements of quality care (Cleland et al., 2021; Ibrahim et al., 2020), yet empirical and observational studies suggest these needs remain insufficiently met in many facilities (Australian Aged Care Quality Agency, 2015; Australian Institute of Health and Welfare, 2023). These gaps reflect not only resource and workforce pressures but also broader challenges in designing care environments that support the psychosocial processes known to sustain well-being in later life, including belonging, role continuity, and perceived competence (Fitzpatrick & Tzouvara, 2019; Yeung et al., 2017).

As population aging accelerates globally, the World Health Organization has called for transformative change in care models and support systems (World Health Organization, 2024, 2025). In Australia, close to 200,000 people live across nearly 2,700 residential aged care facilities, with demand for care projected to surge (Australian Institute of Health and Welfare, 2023). The implementation of aged care reforms and new standards (Aged Care Quality and Safety Commission, 2025), as well as the predicted tripling of Australians aged 85 and over requiring care over the next 30 years (The Treasury, 2023), underscore the urgency of effective and scalable psychosocial interventions in RACHs.

Intergenerational practice has emerged as one response to these challenges, particularly in the context of age-segregated institutions and wider societal ageism. Intergenerational programs aim to bring people of different generations together in mutually beneficial activities that promote social connection, learning, and respect (Cartmel et al., 2018; Radford et al., 2016, 2018). Such programs align with global policy initiatives, including the World Health Organization’s Global Campaign to Combat Ageism, which highlights intergenerational contact as a mechanism for fostering social cohesion and wellbeing across the life course (World Health Organization, 2021).

Shared-site intergenerational programs (SSIPs) represent a distinctive model in which services for different generations are co-located and delivered alongside structured or informal intergenerational engagement (Jarrott & Lee, 2023; Radford et al., 2018). Evidence to date indicates that these programs are concentrated primarily in the United States, where a national profile study identified at least 95 operating shared sites serving more than 25,000 participants. These sites encompass diverse service models, with adult day services and early childhood education emerging as the most common pairing (Jarrott & Lee, 2023). Despite this growth, the broader international evidence base remains limited. A recent scoping review identified only nine empirical studies examining shared-site intergenerational care programs, with seven conducted in North America and one conducted in Australia (Rawlings-Way et al., 2026). This suggests that, while conceptually appealing and increasingly promoted, SSIPs remain under-researched and unevenly developed across different national and policy contexts.

The current evidence also suggests that SSIPs may enhance mood, social engagement, and sense of purpose among older adults while also benefiting children, families, and staff (Gigliotti et al., 2005; Jarrott & Bruno, 2007; Jarrott et al., 2006; Kuehne & Kaplan, 2001; Radford et al., 2018; Weeks et al., 2016). At the same time, studies report mixed outcomes and ongoing challenges, including tailoring activities to diverse abilities, avoiding infantilization, clarifying roles, and sustaining programs over time (Heyman & Gutheil, 2008; Jarrott & Bruno, 2007; Radford et al., 2022; Salari, 2002).

In the Australian context, SSIPs remain relatively novel and underreported. While individual initiatives have emerged, such as the Grandfriends trial (Low et al., 2015), the shared-site model (particularly integration of residential aged care and early childhood services within purpose-built or co-located environments) has been identified as an emerging approach. Consistent with international observations that such models are less visible outside North America, there is limited published research documenting their implementation, outcomes, and sustainability within Australia (Kirsnan et al., 2023). Accordingly, this study examined an SSIP situated within this emerging landscape, contributing empirical insight into how such models operate in practice.

To date, most research has focused on whether intergenerational programs produce benefits, with far less attention to how and why outcomes vary across settings and populations (Fakoya et al., 2021). Without explanatory insight, it remains difficult to determine whether mixed findings reflect implementation challenges, contextual constraints, or mismatches between program design and residents’ psychosocial needs (Jarrott et al., 2021; Stame, 2010). Realist evaluation offers a way to address this gap by examining how specific program resources interact with contextual conditions to trigger underlying mechanisms that generate outcomes, thereby illuminating what works, for whom, and under what circumstances.

Objectives

This study reports on a realist evaluation of one of Australia’s few shared-site intergenerational programs, a collaboration between Uniting AgeWell’s Andrew Kerr Care Community and The Herd Intergenerational Learning Centre (hereafter known as Andrew Kerr Care and The Herd, respectively), which co-locates residential aged care and early childhood education and care on a single site. Situated within a policy environment calling for innovation and improved psychosocial care, the evaluation aimed to:

1. Identify and explain the mechanisms through which a shared‑site intergenerational program contributes to older adults’ psychosocial well-being and, secondarily, staff experiences;

2. Examine the contextual factors (e.g., environment, participant characteristics, program features) that enable or constrain positive outcomes; and

3. Generate practice-relevant insights to inform the design, implementation, and sustainability of SSIPs, or more broadly, intergenerational programs delivered in residential aged care settings.

By elucidating how organizational, relational, and environmental contexts shape psychosocial outcomes, this study contributes to gerontological understandings of wellbeing in later life and offers theory-informed guidance for intergenerational practice in institutional care settings.

Methodology

A realist evaluation approach was adopted to examine how, why, for whom, and under what conditions a shared‑site intergenerational program generated psychosocial outcomes for participating older adults. Realist evaluation is grounded in critical realist philosophy, which assumes that outcomes arise from interactions between program resources and the social, organizational, and institutional contexts in which they are embedded (Pawson & Tilley, 1997; Sayer, 1999). By examining the relationships between context, mechanisms, and outcomes (see Figure 1 for definitions), realist evaluations generate nuanced understandings of the effectiveness, functioning, and adaptability of complex interventions (Dziruni et al., 2025). This heuristic and framework of Context-Mechanism-Outcome configurations is particularly valuable for analyzing complex programs such as SSIPs, as it elucidates how contextual factors and interactions with the initiative contribute to its outcomes (Manzano, 2016; Mukumbang et al., 2020; Pawson, 1996).

Figure 1.

Key definitions of terminology used in realist research methodology.

A core component of realist evaluation is the development and testing of Initial Program Theories (IPTs). IPTs represent provisional hypotheses about how a program is expected to work, informed by prior evidence and stakeholder knowledge. In this study, IPTs (presented in Supplementary Appendix A) were developed prior to data collection through a rapid realist review and expert interviews (reported in Lee et al., under review) and were used to guide both data collection and analysis. Specifically, IPTs informed the development of interview guides (Supplementary Appendix C) and served as sensitizing frameworks during coding, while remaining open to refinement. Through iterative analysis, IPTs were tested, elaborated, and refined into final program theories.

This realist evaluation is reported in accordance with the RAMESES II reporting standards for realist evaluations¹ (Wong et al., 2016). A completed RAMESES II checklist has been provided as Supplementary Material (Appendix B).

Setting

The study was conducted within a shared-site intergenerational program located in Victoria, Australia, involving the co-location of a residential aged care home (Andrew Kerr Care) and an early childhood education and care service (The Herd). The program facilitated regular intergenerational engagement between older adults residing in the aged care home and children attending the co-located early learning center. The program officially commenced in 2023 following the establishment of a formal partnership between the two organizations and an agreement to build the early learning center on vacant land adjacent to the residential aged care home. The early learning center thus operates as a tenant of the aged care organization, with intergenerational programming coordinated through collaborative leadership and shared planning processes. Participants included older adults residing in the aged care service (120 beds) and children enrolled in the early learning center (66 places, ranging from 6 months to 5 years). Participants were not necessarily connected outside the program (e.g., through family or community ties), although both groups were drawn from the local community and shared the same physical environment.

Intergenerational engagement occurred through a range of structured and informal activities designed to support meaningful interaction and participation. They were structured into four distinct tiers of interaction: incidental opportunities and encounters (e.g., interacting in shared areas, spontaneous visits); appropriate lifestyle activities (e.g., Taichi, guest performances); specific intergenerational activities (e.g., music, craft, exercise, cooking; four times a week); and structured volunteering opportunities (e.g., reading program, feeding babies; see Figure 2). Intergenerational principles guiding the program were developed from established intergenerational frameworks such as Generations Working Together and Wildman (2015) (i.e., mutual benefit, agency, and community strengthening) and informed the design and facilitation of activities.

Figure 2.

Different variations of intergenerational engagement offered in the community (adapted and used with permission of the herd intergenerational learning center).

Staff from both the RACH and early childhood services contributed to program delivery. While staff were primarily employed within their respective services, intergenerational activities were facilitated collaboratively, with joint planning, shared supervisors, and designated coordinators supporting implementation.

Participants and sampling

Consistent with realist evaluation methods, sampling was purposive and theory-informed (Renmans & Pleguezuelo, 2023). Participants were selected based on their ability to contribute to the development, testing, and refinement of IPTs. Recruitment, therefore, sought representation across key informant groups, including residents, aged care staff, early childhood educators, and senior managers involved in program design and delivery.

A predetermined sample size was not established. Rather, sample adequacy was guided by principles of information power and explanatory sufficiency (Pawson & Tilley, 1997; Wong et al., 2016). Recruitment sought to capture diverse experiences and contextual conditions relevant to theory refinement across key informant groups. Following recommendations by Malterud et al. (2016), information power was considered throughout data collection and preliminary analysis, with recruitment continuing until sufficient information redundancy had been achieved and no substantively new insights were emerging to inform the refinement of CMOCs. This approach is consistent with other realist evaluations of health and social care interventions that have employed relatively small but information-rich samples (Boddy, 2016; Fakoya et al., 2021).

Eligibility and recruitment

Eligibility criteria varied according to participant group. Older adults were required to have participated in, or have experience of, the intergenerational program and be able to engage meaningfully in a realistic interview. Potential resident participants were initially identified by RACH staff familiar with their cognitive and communication abilities. Older adults who were unable to provide informed consent or meaningfully participate due to significant cognitive, communication, or health-related limitations were not recruited.

Staff participants were eligible if they had direct involvement in facilitating, supporting, coordinating, or overseeing the program. Senior managers and executives were eligible if they held organizational responsibility for program implementation, governance, or strategic oversight.

Residents were approached through facility staff, while staff and managers were recruited through information sessions, organizational communications, and operational meetings. Interested participants received a plain language statement and were provided opportunities to ask questions before deciding whether to participate.

Interview procedure

Semi-structured realist interviews were conducted using interview guides developed from the IPTs and tailored to each participant group (Supplementary Appendix C). Consistent with realist interviewing approaches, interviews explored participants’ experiences of the program as well as their perspectives on how, why, for whom, and under what circumstances outcomes were generated, combining open-ended questions and theory-driven probes to test, refine, and elaborate emerging program theories (Manzano, 2016).

Prior to participation, the researcher reviewed study information with all participants and obtained written informed consent. For resident participants, the researcher additionally confirmed participants’ understanding of the study and their willingness to participate immediately prior to commencing the interview.

Interviews were conducted at a time and location convenient to participants (i.e., within the RACH or ECEC, or online). The researcher reviewed study information verbally and confirmed participants’ understanding and willingness to participate prior to the interview. All interviews were audio-recorded and transcribed verbatim. Participation was voluntary; ongoing consent was monitored throughout the interviews. Interviews were paused or ceased if participants exhibited signs of fatigue, confusion, discomfort, or distress.

Data sources

Multiple qualitative data sources were used to enable triangulation and support realist analysis. Data included semi‑structured realist interviews, organizational policy and procedure documents, and longitudinal staff observation notes.

Policy and procedure documents relevant to the intergenerational program were developed collaboratively by the aged care and ECEC organizations during the establishment of the SSIP. These documents outline the program’s goals, operational standards, and safety protocols for residents, children, and staff. They also specify compliance and legislative requirements, ethical responsibilities, and industry best practices to ensure quality care and risk management.

Lifestyle staff at the residential aged care home, in collaboration with early childhood educators, facilitated all intergenerational activities and routinely documented evaluation notes after each session. These notes include attendance records (resident and child participants), descriptive observations of interactions, resident quotes, and staff reflections on session dynamics, including perceived successes and areas for improvement. These observational data were included to capture the everyday, real-time functioning of the program, providing insight into how interactions unfolded beyond formal interviews. Together, these sources provided insight into both intended and enacted program mechanisms.

Data analysis

Data analysis was conducted using a realist analytic approach, with the aim of identifying and refining CMOCs and synthesizing these into program theories. In line with realist evaluation methodology, analysis was iterative and theory-driven, integrating inductive, deductive, and retroductive reasoning (Wong et al., 2016). In realist terms, retroduction involves asking “what must be true” for these outcomes to occur within specific contexts (Jagosh, 2020; Mukumbang, 2023).

IPTs developed prior to data collection informed early stages of analysis by providing a provisional framework for identifying relevant contexts, mechanisms, and outcomes within the data. These IPTs were not treated as fixed hypotheses but as sensitizing constructs that guided interpretation and were iteratively refined through the analytic process.

Data management and initial coding were supported using NVivo qualitative data analysis software, which facilitated the organization and retrieval of interview transcripts, documents, and observation notes. Analysis proceeded in several stages. First, following Gilmore et al. (2019)’s process, data were subjected to open coding, involving line-by-line coding to identify segments of data relevant to contexts, mechanisms, and outcomes. Both inductive and deductive approaches were applied at this stage: inductive coding allowed identification of new themes, while deductive coding was guided by the IPTs and realist concepts.

Second, codes were refined through selective coding, in which data segments were grouped and synthesized into provisional CMOCs. This stage involved examining relationships between contextual conditions, underlying mechanisms, and observed outcomes. Retroductive reasoning was applied throughout the analytic process to move beyond participants’ accounts and identify the underlying causal mechanisms that could plausibly explain observed outcomes.

CMOCs were subsequently organized and refined using Microsoft Excel to support systematic comparison across cases and data sources. This facilitated the identification of patterns, the testing of relationships between contexts, mechanisms, and outcomes, and the consolidation of CMOCs across participants and settings. CMOCs were also analyzed at multiple levels, including dyadic interactions (e.g., Context-Mechanism; Mechanism-Outcome) and triads (i.e., Context-Mechanism-Outcome) involving broader organizational or facilitative elements (Jackson & Kolla, 2012).

These CMOCs were iteratively tested and refined through comparison across interviews, organizational documents, and observational data. Multiple data sources were used to examine convergence and divergence in accounts, supporting the refinement of explanatory program theories. This approach reflects a realist logic of triangulation; whereby different forms of evidence are used to test and elaborate context-mechanism-outcome relationships. These refined CMOCs were then synthesized into higher-order program theories that explain how and under what conditions the program generated outcomes. Credibility was enhanced through team discussion, secondary review of coded data, and transparent documentation of analytic decisions.

Positionality statement

The lead author (LL) has a professional background in the psychological sciences and health research, with prior and ongoing experience with intergenerational programs and mixed-methods evaluation. This informed familiarity with the study context and sensitivity to relational and organizational dynamics within intergenerational programs. Reflexive practices, including memo writing and iterative discussions with the research team of researchers with varied but relevant expertise and experience (including aged care, nursing, education, mental health, and realist methodology), supported critical interpretation and helped minimize the influence of researcher assumptions on the development of the program theories.

Ethics

Ethics approval was obtained from the University’s Human Research Ethics Committee (approval number: 2023-005). The participating aged care organization provided governance approval. All participants provided informed consent, and confidentiality was maintained through de-identification of participant data and secure data storage procedures.

Results

Participants and data sources

A total of 33 key informants and users were interviewed, comprising 14 older adults or grandfriends who participated in the program, seven early childhood educators and six aged care staff who were involved in program facilitation, and six senior management or executives (four from aged care, two from ECEC) who were involved in planning and operationalizing the program. Demographic characteristics of these key informants are presented in Table 1.

Table 1.

Demographic characteristics of interview participants.

Characteristic	Residents (n = 14)	Staff (n = 13)	Management (n = 6)
Gender (%)	12 women (85.7)	13 women (100)	5 women (83.3)
Age	Mean: 87.3 years (74–100 years)	Mean: 38.8 years (23–60 years)	Mean: 47.8 (35–56 years)
Country of birth (%)	Australian-born: 12 (85.7)	Australian-born: 12 (92.3)	Australian-born: 4 (66.7)
	Overseas-born: 2 (14.3)	Overseas-born: 1 (7.7)	Overseas-born: 2 (33.3)
Highest level of education (%)	Secondary college/high school: 3 (21.4)	Secondary college/high school: 1 (7.7)	Post-graduate: 3
	Certificate III and/or IV: 1 (7.1)	Certificate III and/or IV: 5 (38.5)	Undergraduate: 3
	Diploma: 2 (14.3)	Diploma: 3 (23)
	Undergraduate degree: 2 (14.3)	Undergraduate degree: 2 (15.4)
	Postgraduate degree: 1 (7.7)	Postgraduate degree: 2 (15.4)
	Other: 5 (35.7)—Year 2, Grade 6, Year 8, Year 9, Year 10

Resident participants (n = 14) had lived at Andrew Kerr Care for 4 to 36 months (mean = 1.8 years), with 29% diagnosed with dementia or mild cognitive impairment. Staff (n = 13) had 3 months to 36.5 years of role tenure (mean = 9.8 years), and 6 months to 36.5 years of industry experience (mean: 9.3 years), with 46% being full-time. Staff involvement in the intergenerational program averaged 3 days/week. Senior managers (n = 6) reported 20 months to 30 years of industry experience (mean = 15.4 years) and 20 months to 6.5 years at these sites (mean = 4 years).

Six policy and procedure documents were analyzed. These were collaboratively developed between the two organizations; five were from the ECEC (“Guiding Principles”; “Project Risks and Consideration of Resident-Child Restrictions”; “Child Protection Policy”; “Control of Infectious Diseases”; and “Sick Children Policy”) while one was from the aged care organization (policy for lifestyle staff).

Observations and notes from program facilitators (specifically, lifestyle staff in the RACH) were analyzed across 19 months from program commencement (February 2023 to August 2024).

Program theories

Data informed the development and refinement of 20 CMOCs, which were iteratively refined and synthesized into seven program theories. These program theories represent higher-order explanations of how and under what conditions the shared-site program generated outcomes for residents, staff, and the organization. Each program theory draws on multiple CMOCs and is supported by illustrative qualitative data. The following section presents how these CMOCs and program theories were developed. Table 2 provides an example of the CMOCs for Program Theory 1; for a full list of the 20 CMOCs with illustrative data, please see Supplementary Appendix D.

Table 2.

Program Theory 1’s CMOCs: welcoming, safe and accessible environments.

No./Title	Context	Mechanism	Outcome
1/Comfort through continuity	Regular, sustained intergenerational interactions are integrated into the routine of the aged care home, with staff scaffolding participation and respecting resident autonomy.	Familiarity develops through routine and spontaneous engagement; participant confidence increases as uncertainty is reduced.	Cross-generational comfort and confidence; reduced anxiety about participation; increased intergenerational connections.
2/Connecting organically	Aged care homes provide physically and socially welcoming environments, enabling informal, participant-led intergenerational encounters (including observation).	Gentle participant-led exposure and observation build trust, normalize difference, and foster mutual recognition.	Organic social acceptance, deeper relationships, and breaking down of age-based stereotypes.
8/Presence revitalizes the home	Young children are regularly present in aged care settings, supported by leadership structures and skilled facilitation.	The presence of children evokes joy, reminiscence, nurturing instincts, and sensory stimulation in older adults.	Enhanced emotional well-being, increased social and physical activity, reinforced identity, and reduced loneliness within a family-like community environment.
15/Accessibility through the built environment	Early childhood and aged care facilities have easy, flexible access between spaces, designed to meet the needs of both generations.	Reduced logistical and emotional barriers to foster inclusivity and spontaneous participation in shared spaces.	Increased social connection, belonging, and psychosocial well-being among older adults.
17/Trust/safety through governance	Programs align with both aged care and early childhood regulations and ensure compliance and safety processes are adhered to.	Clear governance and robust risk management processes create perceptions of reliability, safety, and care.	Enhanced physical, psychological, and emotional safety; strengthened trust and participation; sustained psychosocial outcomes.

Program Theory 1: welcome, safe and accessible environments [CMOCs 1, 2, 8, 15, 17]

Welcoming, safe and accessible environments were foundational for enabling older adults to engage comfortably, confidently, and meaningfully in intergenerational initiatives. When interactions occurred in familiar, proximate spaces within the aged care home, residents experienced participation as low-risk and manageable, reducing anxiety about engagement. Regular exposure in familiar communal spaces, as well as incidental encounters (viewing rooms, lounges, fences, and hallways), normalized intergenerational presence: “They’re just here, you don’t have to go anywhere” (Resident 2). Program designers described activity tailoring to residents’ capacities: “We’re always making sure activities… are suitable to their own level of cognition and physical ability…trying to make sure people aren’t left out. That it’s of value to them” (Executive 6). Co-location enabled both scheduled programming and spontaneous visits, strengthening connection: “They can go down and see the children any time…I think it’s just a part of the normal for us now” (RACH Staff 6).

Organizational policies and governance structures reinforced perceptions of safety and trust. Risk management protocols, infection control measures, and clearly articulated staff responsibilities functioned as contextual resources that enabled residents and staff to interpret the program as trustworthy and well-regulated. For example, inclusive activity planning and ways to reduce risk (e.g., prompts for children to speak clearly for residents with hearing loss and adaptation of games for seated play; Policy & Procedure 3). Governance set a minimum staff-to-resident ratio of 1:10 during intergenerational activities and specified lifestyle staff responsibilities for planning, supervision, and delivery (Policy & Procedure 5).

Staff observation notes illustrated how small environmental adjustments supported these processes. Introducing shared tables and height-adjusting furniture facilitated eye-level interaction and mutual curiosity, while chair-based activities enabled participation for residents with limited mobility. However, outcomes varied where health status, mobility limitations, or scheduling constraints restricted access. Flexible practices, such as brief spontaneous visits or children visiting residents’ rooms, partially mitigated exclusion, highlighting that accessibility operated as both a physical and relational condition shaping psychosocial outcomes. Overall, accessibility functioned both physically and relationally, where reciprocal design and responsive facilitation produced an ease of connection central to sustained participation: “There’s this beautiful ease of access–ease of connection and relationship, at the heart of it all” (Educator 6).

Program Theory 2: respecting choice and voice [CMOCs 3, 5, 16]

Empowering residents to choose whether, when, and how to participate was central to motivation, dignity, and ongoing engagement. When participation was clearly voluntary, and residents were supported to decide whether, when, and how to engage, they interpreted intergenerational activities as autonomy-affirming rather than imposed. This activated mechanisms of self-determination and meaning, supporting continued involvement. As one staff member emphasized, “We absolutely don’t push [residents] to come if they don’t want to.” (RACH Staff 4). Facilitators spoke of inviting initiative while ensuring comfort: “It’s giving them enough initiative and confidence to be that older role model but also setting it up so they’re comfortable” (Executive 4).

Formal organizational processes, including activity calendars, reminders, and feedback mechanisms, provided opportunities for residents to express preferences and feel recognized. Organizational policies formalized the residents’ voices, for example, by organizing “Resident and Representative Meetings” to solicit preferences and discuss ideas for intergenerational activities, and feedback postcards to capture ongoing input (Policy & Procedure 5). In practice, the translation of resident input into program design was uneven. Observation and interview data showed that while informal feedback occasionally prompted practical adjustments, such as splitting large groups or modifying activities, systematic co-design was varied. Declines in attendance were attributed to timing conflicts (“some are still getting dressed” [RACH Staff 1]), novelty fatigue, or repetitive programming.

Where choice was accompanied by responsive facilitation and varied activities, empowerment mechanisms were sustained, contributing to psychosocial well-being. Conversely, when resident preferences were inconsistently acted upon, autonomy could inadvertently lead to disengagement. These findings underscore that choice alone was insufficient; it required active facilitation to translate autonomy into meaningful participation.

Program Theory 3: reciprocity and mutual learning [CMOCs 3, 6, 9]

Reciprocal exchange, where older and younger participants both teach and learn, activated mechanisms of pride, mastery, and social connection. When residents were positioned as contributors rather than passive participants, they experienced renewed purpose and generativity. Participation enabled residents to contribute skills, stories, and care, fostering generativity and renewed purpose: “It’s allowed them to give back, to feel useful, to have purpose again” (RACH Staff 1). Recognition of their strengths and contributions from children and staff reinforced identity and belonging, lifting mood and engagement: residents “see themselves as being important in that child’s development” (Executive 2). Learning from children inverted assumptions of who holds knowledge and triggered new identities as co-learners: “They prove to themselves that they can do more than they think they can… it’s definitely good for their confidence” (RACH Staff 3).

Observation data captured these reciprocal moments. Residents taught children games from their own childhood, read books, assisted with crafts and gardening, and volunteered within the early learning center. One resident who assisted children during mealtimes described feeling “so good to be able to help” (resident quote, observation), illustrating how contribution reinforced identity and emotional well-being. Children, in turn, introduced new songs, signs, and ways of playing, positioning residents as learners as well as teachers.

Policy frameworks and facilitation practices supported reciprocity by ensuring appropriate supervision and adapting activities for participation (Policy & Procedure 3, 5). However, reciprocity was not automatic. Where facilitation was limited, or residents were repeatedly positioned in narrow roles, there was potential to reinforce hierarchies rather than disrupt them. Psychosocial benefits were greatest when reciprocity was intentionally scaffolded, recognized, and embedded within the program’s design.

Program Theory 4: building relationships and acceptance [CMOCs 2, 4, 20]

Repeated, supported intergenerational encounters fostered affective bonds that reduced loneliness and enhanced emotional well-being. When older adults interacted regularly with the same children, they experienced continuity and familiarity, enabling trust and deeper connection to develop over time. Children’s non-judgmental acceptance was particularly salient for residents with cognitive or physical impairments, challenging internalized stigma and ageism: “Our residents [living] with dementia… kids just don’t care. That kind of complete lack of judgement has been really positive” (Executive 6). Staff noted the contrast with once-off programs, finding that ongoing contact with the same children fostered deep friendships and increased children’s and older adults’ willingness to engage and “come out of their shells” (RACH Staff 4).

Playful engagement and informal interactions, such as games, music, and spontaneous greetings, lowered social barriers and generated joy and anticipation. This granted residents psychological permission to play: “Their childlike personalities are coming out, and they feel confident that they can actually do things like that because it’s accepted, because the children are there. So, I find that’s a beautiful thing; that they’re allowed to let that out… Have a little bit of fun and have a little bit of play” (Executive 3).

Residents described looking forward to visits, which provided emotional uplift and a renewed sense of purpose: “It keeps you young… gives you something to look forward to, to wake up in the morning and think, ‘Oh good, I’m going to see the children today’” (Resident 13). Observation notes captured moments of recognition and affection, including children seeking out specific residents and shared celebrations that extended beyond structured activities.

However, relationship-building also carried risks. Program facilitators noted that less mobile or cognitively impaired residents sometimes received less attention from children, while strong emotional attachments occasionally resulted in distress when routines changed or participants were absent. Policies addressing sensitive transitions and staff facilitation were critical for mitigating these unintended outcomes. Overall, psychosocial benefits were greatest when relationships were nurtured intentionally and inclusively, with facilitation attuned to residents’ diverse emotional needs.

Program Theory 5: staff facilitation, development, and fulfilment [CMOCs 10, 13, 14, 18]

Staff facilitation was central to the success of meaningful intergenerational engagement. When facilitators were values‑aligned, supported, and confident, they scaffolded interactions that balanced safety with spontaneity, fostering inclusive participation: “It’s just been wildly successful because of the people that they’ve chosen to be here and be a part of it” (Educator 3). Staff described the program as professionally fulfilling, noting emotional rewards and opportunities for skill development. Staff expressed pride, belonging, and renewed passion for their work, framed by a sense of contribution to community wellbeing and describing the work as “moving,” “humbling,” and “beautiful.” As one participant summarized, the program “made me feel like I have more to contribute to society” (RACH Staff 5).

On-the-job learning, mentoring, and cross-sector collaboration enhanced staff capability and confidence. Training in areas such as manual handling and dementia-informed practice enabled educators to support residents safely, while reflective supervision helped staff manage emotional demands associated with attachment, decline, and loss. These supports activated mechanisms of professional pride and purpose, contributing to staff wellbeing and sustained engagement. Policies scaffolded this work through participant-safe regulation and mandatory reporting across both organizations, requiring all staff and volunteers to understand legal responsibilities and to treat participants with respect (Policy & Procedure 1). Governance sets roles and responsibilities (management oversight; lifestyle staff planning, coordination, and supervision; volunteer guidance), minimum supervision ratios, and training expectations for both RACH and childcare staff so “everyone knows the goals of the project” (Policy & Procedure 5).

Constraints emerged where staffing levels, documentation demands, or limited care staff availability restricted facilitation capacity. Emotional labor was particularly pronounced, underscoring the importance of organizational recognition and support. Where facilitation was under-resourced, engagement quality and psychosocial outcomes were diminished. Thus, staff wellbeing functioned both as an outcome and a condition for program success.

Program Theory 6: organizational culture and leadership [CMOCs 7, 11, 12, 17]

Leadership commitment and organizational culture played a pivotal role in legitimizing and sustaining the intergenerational program. Leaders who visibly modeled respect, kindness, and collaboration fostered a shared sense of purpose and trust across aged care and early childhood teams. As one educator noted, leadership “models beautiful, caring, respectful interactions,” which shaped everyday practice (Educator 7).

Clear governance structures, role clarity, and regular communication translated vision into operational support. These contexts activated mechanisms of buy-in and psychological safety, encouraging staff to invest emotionally and professionally in the program. At the same time, centralized planning sometimes limited staff and resident ownership. While many staff appreciated leadership-led coordination, others perceived limited opportunities for co-design, particularly regarding activity selection and resident preferences.

Policies aligned the program with organizational values and regulatory requirements, reinforcing reliability and accountability (Policy & Procedure 5). However, sustaining momentum required balancing strong leadership with opportunities for shared ownership. Where leadership fostered collaboration rather than control, engagement and sustainability were strengthened.

Program Theory 7: anchoring in community and local culture [CMOCs 7, 15, 19]

Alignment with local community values anchored the program within everyday organizational life, fostering authenticity and sustained participation. The shared-site model resonated with family-oriented community norms, encouraging enrollment, advocacy, and intergenerational identification: “Having the right demographic…families who are really vested. Also, we’ve had a lot of like multicultural families enrol, which again adds to that same element above of family buy-in and family belief in the model because they grew up with their grandparents” (Executive 4).

Community events and shared traditions, such as festive celebrations and picnics, strengthened relational ties and evoked reminiscence among residents. Observation notes described residents’ emotional responses to these events, including memories of childhood and family life, which reinforced belonging and continuity of identity. Policies reiterated child- and resident-safe obligations across organizations, volunteers, and visitors, embedding shared norms of respectful engagement (Policy & Procedure 1). Cross-organizational cooperation further supported sustainability, with shared resources and mutual assistance reinforcing a sense of collective stewardship: “You have to have that connection and relationship with the organization next door… it flows good when you’re on the same page” (Educator 5).

While local alignment enhanced resonance, it also carried risks of exclusion if cultural assumptions were not actively examined. Policies emphasizing inclusivity and participant safety were essential for ensuring diverse residents and families felt represented. When effectively anchored, the program became integrated into routine practice rather than a discrete activity, supporting long-term resilience. “The Herd has really become; it’s part of who we are. It’s not just an activity that we do here and there” (Executive 2).

Overall program theory

Taken together, the seven program theories describe how SSIPs generate psychosocial wellbeing in residential aged care through interrelated relational, organizational, and environmental pathways. Rather than operating as discrete mechanisms, these processes function synergistically, shaping whether intergenerational engagement is experienced as meaningful, inclusive, and sustaining over time. Additionally, the program theories demonstrate that outcomes were not uniformly positive but contingent on the alignment of contextual conditions, facilitation practices, and participant capacities. While positive psychosocial and organizational outcomes were evident, variation across contexts highlights the importance of supportive environments, skilled facilitation, and responsiveness to participant preferences. Table 3 provides a detailed illustration of the seven refined program theories.

Table 3.

Seven refined program theories presented as context, mechanism-resource, mechanism-response, outcome, unintended outcomes, and because (mechanism).

Program theory	Context-mechanism-outcome configuration
Program Theory 1: Welcoming, safe, and accessible environments	Context: Environments are psychologically, socially, and physically safe and accessible, supported by organizational norms and physical design that enable proximity and visibility, with staff scaffolding and organic interaction opportunities. Mechanism-resource: Staff scaffolding and opportunities for interaction within a safe, accessible environment Mechanism-response: Older adults interpret these opportunities as trustworthy and welcoming, reducing uncertainty about intergenerational programming and triggering feelings of inclusion, comfort, and confidence. Outcome: Normalization of intergenerational participation and strengthened social bonds, contributing to psychosocial well-being. Unintended outcome: Informal interactions may inadvertently exclude less mobile or isolated residents if scaffolding and environmental adaptations are insufficient. Because: When environments feel safe and are scaffolded by staff, older adults’ uncertainty and anxiety decrease, making them feel included and confident, which normalizes participation and strengthens social bonds.
Program Theory 2: Respecting choice and voice	Context: Older adults are encouraged to exercise autonomy in their participation, and their input and feedback shape programming. Mechanism-resource: Provision of choice and structured feedback channels. Mechanism-response: Participants feel recognized and acknowledged as part of the program, increasing motivation to engage. Outcome: Meaningful and sustained engagement, as well as empowerment. Unintended outcome: Emphasizing autonomy might overwhelm some participants who prefer more structure, potentially reducing participation or increasing anxiety about decision-making. Because: When older adults can exercise autonomy and have their input valued, this recognition increases their motivation and sense of belonging, leading to sustained and empowered engagement.
Program Theory 3: Reciprocity and mutual learning	Context: Both generations have reciprocal opportunities to share skills, stories, and learning. Mechanism-resource: Activities designed for mutual exchange and validation of contributions. Mechanism-response: Participants experience mastery, pride, and deeper connections with children. Outcome: Enhanced meaning in life, increased self-esteem, and challenged ageist stereotypes. Because reciprocal: opportunities for sharing and learning allow participants to experience mastery and pride while forming deeper intergenerational connections, reducing loneliness, and challenging stereotypes. Unintended outcome: Reciprocal interactions may unintentionally reinforce stereotypes if participants rely on limited roles or if unequal power dynamics persist.
Program Theory 4: Building relationships and acceptance	Context: Programs support repeated, individualized, and organically evolving interactions between older adults and children, facilitated by non-judgmental acceptance from children. Mechanism-resource: Structured opportunities for continuity and personalized engagement. Mechanism-response: Older adults feel accepted, develop trust, and form deeper emotional bonds. Outcome: Emotional nourishment and joy, meaningful social connections, and challenging of negative ageist stereotypes. Because: Repeated and individualized interactions foster feelings of acceptance and trust among older adults, resulting in strong emotional bonds and meaningful relationships that nourish well-being. Unintended outcome: Strong emotional attachments, if not sensitively managed, could lead to distress when children leave the program. Emphasis on repeated individualized interactions might exclude those who do not form such bonds.
Program Theory 5: Staff facilitation, development, and fulfilment	Context: Staff are skilled, supported, and fulfilled facilitators through training and teamwork. Mechanism-resource: Professional development and supportive work environments (e.g., cross-sector resource sharing, reflective practice, and supervision). Mechanism-response: Staff feel empowered to cultivate inclusive settings and model positive relationships. Outcome: Greater job satisfaction, staff fulfilment and well-being, and richer intergenerational outcomes. Because professional development and teamwork empower staff to model inclusivity and nurture positive relationships, directly enabling richer outcomes for both themselves and participants. Unintended outcome: High expectations on facilitators might lead to burnout or job dissatisfaction if resources and support are insufficient.
Program Theory 6: Organizational culture and leadership	Context: Leadership invests in intergenerational practice, embeds it in governance, and fosters trusted collaboration with partners. Mechanism-resource: Aligned leadership and collaborative organizational support. Mechanism-response: Participants and staff develop a shared vision, sense of purpose, trust, and willingness for ongoing program improvement. Outcome: Increased buy-in from residents and staff, and program engagement and sustainability. Because: When leadership and collaborative organizational support is aligned, participants and staff share vision and trust, fueling buy-in, engagement, and sustainability for intergenerational programs. Unintended outcome: Institutional focus on intergenerational programs might inadvertently divert attention or resources from other critical areas of care, causing discontentment among other residents or staff.
Program Theory 7: Anchoring in community and local culture	Context: Programs are tailored to local community and cultural values, and cultivated in home-like environments. Mechanism-resource: Recognition and incorporation of local identity and traditions. Mechanism-response: Participants experience shared meaning and acceptance, fostering a sense of belonging. Outcome: Increased social capital, community cohesion, and long-term program resilience. Unintended: Tailoring to local culture might unintentionally exclude minority groups if cultural assumptions are too narrow or if diversity is not actively embraced. Because: Programs embedded in local traditions and home-like environments promote authentic acceptance and shared meaning, cultivating belonging, cohesion, and resilience within the community.

At the core of the overall program theory is the proposition that psychosocial wellbeing is generated when older adults encounter intergenerational engagement as safe, valued, and socially meaningful within their everyday care environment. Welcoming and accessible physical spaces (Program Theory 1) reduce uncertainty and anxiety, creating the conditions for participation. Within these contexts, respect for choice and voice (Program Theory 2) enables residents to interpret engagement as autonomy-affirming rather than imposed, activating motivation and dignity. Reciprocal exchange and mutual learning (Program Theory 3) then allow residents to occupy valued social roles, fostering purpose, generativity, and identity continuity.

These relational mechanisms are sustained through repeated interactions that support relationship-building and acceptance (Program Theory 4), particularly where children’s nonjudgmental presence challenges age- and impairment-related stigma. Skilled facilitation and staff fulfilment (Program Theory 5) are essential for scaffolding these interactions, managing emotional complexity, and translating organizational intentions into everyday practice. Organizational culture and leadership (Program Theory 6) legitimize intergenerational work, embedding it within governance structures and signaling its value to staff and residents. Finally, anchoring the program within local community values and practices (Program Theory 7) enhances authenticity, belonging, and long-term sustainability.

Importantly, the overall theory also highlights conditions under which psychosocial benefits may be weakened or undermined. Limited accessibility, uneven facilitation, constrained resident voice, or insufficient organizational support can disrupt these pathways, leading to disengagement, exclusion, or emotional strain. Strong affective bonds, while beneficial, also require careful facilitation to mitigate distress associated with disrupted routines or attachments. Thus, psychosocial wellbeing is not an automatic outcome of co-location but emerges through ongoing alignment between relational practices, organizational contexts, and participant needs.

This overall program theory advances understanding of psychosocial wellbeing in a residential aged care setting by demonstrating how care environments can be reoriented toward relational, meaningful engagement. It underscores that interventions targeting wellbeing in later life must attend not only to program activities but also to the organizational and social conditions that enable older adults to experience connection, contribution, and recognition.

Discussion

This realist evaluation examined how and why a shared-site intergenerational program influenced psychosocial wellbeing in residential aged care, for whom, and under what conditions. Previous research has documented positive outcomes associated with intergenerational programs, including improved mood, enjoyment, and social engagement (e.g., Heyman & Gutheil, 2008; Low et al., 2015). However, much of this literature has focused on whether programs “work,” with limited attention to how outcomes are generated or why effects vary across settings (Jarrott et al., 2021; Rawlings-Way et al., 2026). By applying a realist approach, this study extends existing evidence by elucidating the causal pathways through which intergenerational programs shape psychosocial wellbeing in institutional care contexts.

Our study confirms that SSIPs can deliver similar benefits but underscores that these are contingent on factors such as autonomy, reciprocity, and organizational support. The findings suggest that mixed results reported in earlier studies may reflect differences in contextual support and implementation rather than theoretical limitations of intergenerational practice itself (Stame, 2010). This aligns with Cohen-Mansfield and Muff (2021) emphasis on preparation, guidance, and monitoring as critical processes and supports Jarrott et al. (2021) call for theory-informed implementation.

Consistent with prior literature, participants in this study reported psychosocial benefits such as enhanced emotional well-being, increased social connection, and renewed sense of purpose (Jarrott & Bruno, 2007; Jarrott & Lee, 2023; Rawlings-Way et al., 2026). However, this evaluation extends existing knowledge by demonstrating that these outcomes are contingent on specific mechanisms, such as feelings of safety, autonomy, and reciprocity, activated within supportive contexts. For example, safe and accessible environments reduced anxiety and normalized participation, echoing Fang et al. (2023) emphasis on inclusive, age-friendly spaces. Similarly, mechanisms of empowerment through choice and voice align with theories of person-centered care, which stress autonomy as a determinant of wellbeing in aged care (Fitzpatrick & Tzouvara, 2019).

Our findings also reinforce the importance of reciprocity and mutual learning, which intergenerational theory highlights as central to fostering generativity and challenging ageist stereotypes (Whitehouse & George, 2018). Residents’ opportunities to contribute skills and knowledge not only enhanced their sense of mastery and identity but also created meaningful two-way exchanges with children, an aspect underexplored in previous SSIP evaluations. This resonates with the proposed concept of “intergenerativity,” which frames intergenerational engagement as a dynamic process of mutual growth rather than a unidirectional transfer of care or knowledge (Whitehouse, 2017; Whitehouse & George, 2018).

Importantly, this study underscores that SSIPs are not inherently effective by virtue of co-location alone. Organizational culture and leadership emerged as critical contextual enablers, legitimizing the program and sustaining staff engagement—a finding consistent with Jarrott et al. (2019) model of evidence-informed principles for intergenerational practice. Conversely, when structural supports such as staff training, reflective supervision, and collaborative planning were insufficient, mechanisms of inclusion and reciprocity were weakened, risking disengagement. These observations mirror Cohen-Mansfield and Muff (2021) assertion that implementation failure, rather than theoretical failure, often explains poor outcomes in intergenerational programs.

The design of the physical environment emerged as a critical contextual factor influencing the success of SSIPs involving preschool children and older adults. Our findings indicate that accessible, welcoming spaces, such as open communal areas, flexible layouts, and proximity between aged care and early learning facilities, enabled spontaneous encounters and normalized intergenerational presence. These features activated mechanisms of comfort, safety, and inclusion, which were essential for sustained engagement. This aligns with Norouzi et al. (2023), which emphasizes that spatial design directly shapes the quality and frequency of intergenerational interactions, advocating for adaptable furniture, shared outdoor spaces, and visual connectivity to foster reciprocity and belonging. Similarly, Farrell (2025) highlights the role of play in intergenerational spaces, noting that environments should support playful, creative interactions that allow older adults to engage meaningfully without infantilization while accommodating children’s developmental needs. Participatory design approaches that incorporate input from both generations are recommended to ensure environments are not only physically accessible but also psychologically safe and culturally resonant. Taken together, these insights reinforce that SSIPs should move beyond co-location to intentionally design environments that activate mechanisms of safety, accessibility, and reciprocity—key drivers of psychosocial wellbeing and program sustainability.

Finally, this study highlights nuanced risks associated with strong affective bonds, such as anticipatory grief or feelings of exclusion, which have received limited attention in prior research. Addressing these risks require sensitive facilitation and ongoing monitoring, underscoring the need to treat SSIPs as complex social interventions that require iterative adaptation rather than static models.

Practical relevance

Findings from this realist evaluation demonstrate that shared‑site intergenerational programs are complex interventions requiring deliberate attention to design, delivery, and sustainability (see Figure 3).

Figure 3.

Practical relevance of findings for program design, delivery, and monitoring.

Planning and designing

Effective programs begin with environments that are physically, psychologically, and socially safe and accessible for all participants. Design features should minimize logistical barriers, support spontaneous interaction, and comply with aged care and early childhood regulations. Co-design with community stakeholders helps align programs with local values, enhancing authenticity and buy-in. Embedding opportunities for participant choice and voice during planning fosters autonomy and ownership while allowing flexibility for organic program development over time.

Delivery and implementation

Successful implementation depends on skilled facilitation and adaptive practice. Staff require training to scaffold engagement across diverse cognitive and physical abilities and to respond sensitively to individual preferences. Varied, meaningful activities and repeated interactions with familiar participants support trust, continuity, and identity reinforcement. At the same time, emotional risks—such as exclusion or disrupted attachments—necessitate proactive management through reflective supervision and sensitive facilitation.

Monitoring and sustainability

Long‑term sustainability is shaped by organizational culture and leadership. Visible leadership commitment, cross‑sector collaboration, and integration into routine workflows normalize intergenerational practice and prevent siloing. Ongoing staff development, mentoring, and emotional support are essential to maintain confidence, prevent burnout, and sustain high‑quality engagement.

Strengths and limitations

A key strength of this study is its realist approach, which moves beyond “does it work?” to explain “how and why” SSIPs function in practice. By generating context-mechanism-outcome configurations, this research provides nuanced evidence for policy and practice. The inclusion of multiple perspectives enhances the credibility and transferability of findings. To our knowledge, there has only been one other realist evaluation of an intergenerational program involving older persons with dementia conducted in Scotland (Emond & Kelly, 2025). This research provides novel information and adds to understanding of SSIPs and intergenerational programs in Australian and aged care settings more generally.

Study limitations include the single-site design, which constrains transferability. While the program was novel in the Australian context, findings may not fully translate to settings with different organizational cultures or demographics. Additionally, data were collected during early implementation, so long-term sustainability and outcomes remain unknown. Future research should examine SSIPs across diverse contexts, incorporate longitudinal designs, and explore impacts on children and families. Comparative realist evaluations could further refine program theories and inform scalable models. Additionally, the participant sample was predominantly composed of women. Consequently, the program theories developed through this evaluation may more strongly reflect the experiences and perspectives of women participants. Further research across more gender-diverse samples would assist in assessing the transferability of the findings to other contexts.

Conclusion

This study demonstrates that SSIPs can enhance the psychosocial wellbeing of residents and staff fulfilment when implemented with attention to safety and inclusion, autonomy, reciprocity, and organizational culture. Rather than viewing SSIPs as simple co-location initiatives, they should be understood as complex interventions requiring adaptive design and sustained leadership. By elucidating the mechanisms underpinning success, this research provides a foundation for evidence-informed practice and policy to advance intergenerational care models in Australia and beyond.

Supplementary material

Supplementary material is available at The Gerontologist online.

Funding

This work was supported by author L.L.’s Deakin University Postgraduate Research Scholarship as part of their doctoral candidature.

Conflicts of interest

The authors have no conflicts of interest to declare.

Data availability

Data are not available due to ethical restrictions. The study has not been preregistered.

Author contributions

Lysha Z.H. Lee (Conceptualization [equal], Data curation [lead], Formal analysis [lead], Methodology [equal], Project administration [lead], Writing—original draft [lead], Writing—review & editing [lead]), Patricia Nicholson (Conceptualization [equal], Data curation [supporting], Formal analysis [equal], Methodology [equal], Project administration [supporting], Supervision [equal], Writing—original draft [supporting], Writing—review & editing [equal]), Katrin Gerber (Conceptualization [equal], Data curation [supporting], Formal analysis [equal], Methodology [equal], Project administration [supporting], Supervision [equal], Writing—original draft [supporting], Writing—review & editing [equal]), and Alison M. Hutchinson (Conceptualization [equal], Data curation [supporting], Formal analysis [equal], Methodology [equal], Project administration [supporting], Supervision [lead], Writing—original draft [supporting], Writing—review & editing [equal])