Emerging Empirical Science of Wisdom: Definition, Measurement, Neurobiology, Longevity, and Interventions

Abstract

Wisdom has been discussed for centuries in religious and philosophical texts. However, since the 1970s the field of empirical research on wisdom has been growing, similar to scientific inquires into other seemingly fuzzy psychological constructs such as consciousness, stress, resilience, and well-being. This article seeks to provide an overview of the empirical literature on wisdom in terms of its definitions and measurements, possible neurobiological basis, and evolutionary value, as well as changes with aging and clinical interventions to enhance components of wisdom. Wisdom may be defined as a complex human trait with several specific components: social decision making, emotional regulation, prosocial behaviors such as empathy and compassion, self-reflection, acceptance of uncertainty, decisiveness, and spirituality. These components appear to be localized primarily to the prefrontal cortex and limbic striatum. Emerging research suggests that wisdom is linked to better overall health, well-being, happiness, life satisfaction, and resilience. Wisdom likely increases with aging, facilitating a possible evolutionary role of wise grandparents in promoting fitness of the species. Despite the loss of their own fertility and physical health, older adults help enhance their children’s well-being, health, longevity, and fertility – the “Grandma Hypothesis” of wisdom. We propose a putative model of wisdom development that incorporates genetic, environmental, and evolutionary aspects of this construct. Wisdom has important implications at both individual and societal levels, and warrants further research as a major contributor to human thriving. There is a need for a greater emphasis on promoting wisdom through our educational systems from elementary to professional schools.

Wisdom alone is the science of other sciences.

Plato (427 – 347 BC)¹

Let no one be slow to seek wisdom when he is young nor weary in the search of it when he has grown old. For no age is too early or too late for the health of the soul.

Epicurus (341-270 BC)²

Introduction

Wisdom has been discussed since times immemorial in religious and philosophical literature. Empirical research in wisdom made its appearance in the 1970s, but its pace has accelerated during the last two decades. Still, to many people wisdom remains a fuzzy concept that is difficult to define, operationalize, and measure. In psychiatry, little attention has been paid to wisdom with the exception of pioneers such as Vaillant.^3–5 In this article, we begin with its historical background, followed by a review of empirical definitions and measurements of wisdom, putative neurobiology, relationship to aging, suggested evolutionary value, and finally a summary of emerging research on interventions seeking to enhance components of wisdom. We propose that wisdom is a complex human trait with several specific components: social decision making, emotional regulation, prosocial behaviors, self-reflection, acceptance of uncertainty, decisiveness, and spirituality. Growing research suggests that wisdom is a personally and societally useful construct and has been linked to better overall physical and mental health,^6–11 well-being,¹² happiness,^10,13–15 life satisfaction,^{10,11,16–18} and resilience.⁷ Wisdom likely increases with aging, indicating possible evolutionary role of wise grandparents in promoting fitness of the species by helping enhance their children’s well-being, health, longevity, and fertility.¹⁹

It is worth noting that a number of seemingly fuzzy psychological constructs were previously thought to be non-scientific and non-biological because they could not be defined objectively – e.g., consciousness, emotion, cognition, stress, resilience, well-being. Yet, with advances in neurobiological as well as psychosocial sciences, all these constructs are accepted today as important scientific entities with major implications for psycho-bio-social functioning of individuals. We believe that wisdom is in the early stages of moving from this once-dismissed to later-embraced list of constructs that are amenable to empirical research. This article is intended to be a call for additional research to explore, test, confirm, disprove, or revise specific hypotheses proposed and thereby refine the conceptualization of wisdom presented below.

Historical Background

The concept of wisdom has long historical roots in religion and philosophy.²⁰ Ancient civilizations amassed wisdom literature passed from one generation to the next, often expressed in the form of parables or songs to communicate proper social and moral conduct and provide life advice.²¹ Wisdom is frequently discussed in several ancient texts such as the Sebayt, Egyptian scrolls dating from 2000 BC to 1700 BC, and the Bhagavad Gita, a Hindu philosophical/religious scripture.²⁰ The Old Testament books of Job, Psalms, and Proverbs, also described paths to the attainment of wisdom. Influential ancient eastern thinkers from Confucius to Buddha ruminated on wisdom. Ancient Greek philosophers including Socrates, Aristotle, and Plato described a wise person as one with extensive knowledge that s/he was able to teach others but who was also aware of the limitations of this knowledge.²²

In modern psychology, Hall’s 1922 treatise “Senescence: The Last Half of Life,” may have been the first broad discussion of wisdom.²³ Hall theorized that the function of older adults was to glean wisdom, characterized by calmness, impartiality, and moral knowledge, from their previous experiences. Erikson conceptualized wisdom as the optimal outcome of a conflict between ego integrity and despair that typified the final phase of his postulated eight-stage course of human life.^24,25 Per Erikson, a wise individual is content, with an “informed and detached concern with life itself in the face of death itself.”²⁶

Beginning in the 1970s, early empirical research on wisdom was initiated by Baltes and Smith²⁷ in Germany and Clayton and Birren²⁸ in the US. Baltes, et al.^29,30 believed that wisdom was rare and consisted of five criteria: rich factual knowledge of life’s conditions and changing situations; deep procedural knowledge for dealing with those conditions and situations; lifespan contextualism (understanding how different aspects of life interact); sense of relativism recognizing and respecting differences among individuals and cultures; and acceptance of uncertainties in life.

Clayton and Birren proposed that wisdom consisted of several discrete and measurable components: a reflective component involving introspection and intuition, an affective component involving empathy and peacefulness, and a cognitive component characterized by knowledge and experience.²⁸

Subsequent investigators highlighted other aspects of wisdom. Sternberg’s balance theory of wisdom stated that common good was achieved through the application of tacit knowledge, mediated by a balance of intrapersonal, interpersonal, and extrapersonal interests to achieve a balance among adaptation to and shaping of existing environments and selection of new environments.^31–33 Ardelt conceptualized wisdom as an integration of cognitive, reflective, and affective personality qualities, that are predictive of subjective well-being.^6,34 Staudinger proposed five criteria of wisdom: insight, personal growth, self-awareness of the current context, value relativism, and awareness and management of life’s uncertainties.^23,29,35 Nusbaum, et al. reported that more extensive experiences such as meditation and dance, rather than chronological age, were associated with increased cognitive, affective, and reflective wisdom.³⁶

In the largest and longest investigation of its kind, Vaillant’s Harvard Study of Adult Development examined behaviors and factors that contributed to mental and physical well-being as well as longevity.^5,37 Predictors of successful aging included unmodifiable factors (social class, temperament, physical health, and family history of longevity) and modifiable ones (marriage, coping strategies, physical activity, body weight, alcohol use, and smoking.) Vaillant found that while wisdom and well-being at age 80 years were correlated, their predictors differed.³⁸ Openness to new experiences as a young adult and lifelong psychosocial growth were predictive of wisdom in old age, while emotional stability and extraverted personality were predictive of well-being in old age. Cloninger studied how personality, the integration of temperament and character traits, contributed to well-being. He reported that personality traits of self-directedness, cooperativeness, and self-transcendence contributed to well-being.³⁹ Blazer’s work on successful aging and the role of spirituality/religiosity in mental health highlighted the need to promote practical wisdom.^40–42 Other groups have incorporated spirituality into definitions of wisdom. Achenbaum and Orwoll examined the Book of Job to identify components of wisdom (faith in God, recognition of God’s existence and role, self-transcendence), considering Job the prototypical wise man.⁴³ Perry defined spirituality as “feel[ing] love, fellowship or union with God or a higher being” and “living a spiritual life.⁴⁴” Jason highlighted the difficulty of increasing spirituality through challenging experiences, struggle and resilience.⁴⁵ Wink and Helson defined “transcendent wisdom” as transpersonal skills including self-transcendence and other philosophical approaches.⁴⁶ Spirituality has been defined broadly – from a general awareness of other powers/forces affecting the universe to a more religion-based exemplification of a spiritual life. Our perspective is that spirituality is often interconnected though independent from religiosity; a person can be spiritual without being religious.

Modern pragmatic definitions of wisdom, such as described by Prensky, focus on “the ability to find practical, creative, contextually appropriate and emotionally satisfying solutions to complicated human problems." Technology can be harnessed to make moral, ethical, and pragmatic decisions – through facilitating instantaneous feedback from trusted advisors or gathering input from and disseminating data to large numbers of people at once.⁴⁷

Defining Wisdom

While definitions of wisdom vary throughout the literature, the definitions are descriptive and conceptual. For example, the Oxford English Dictionary defines wisdom as “capacity of judging rightly in matters relating to life and conduct,⁴⁸” while other definitions focus on specific qualities like cognition (Baltes) or balance (Sternberg). The approach highlighted in this review uses empirical methods to operationalize and measure wisdom. There is value to both the holistic and empirical approaches. Ultimately, the basic concept of wisdom is similar – a high-level quality that is useful for optimal functioning in society.

Several methods have been used to derive a consensus definition of wisdom: literature review, expert panel, examination of a scripture, and interviews of older adults. Remarkably, the components of wisdom identified in these different ways were similar.

Literature review

The field of empirical wisdom research has grown considerably as evidenced by a 28-fold increase in the number of articles on wisdom found in a PubMed database search from the 1970s through 2017 (Figure 1).⁴⁹ In a systematic review of the scientific literature on wisdom, Meeks and Jeste identified six common components: general knowledge of life and social decision making, emotional regulation, pro-social behaviors like compassion and empathy, insight or self-reflection, acceptance of different value systems, and decisiveness.⁴⁹ A subsequent literature review⁵⁰ added the components of spirituality, openness to new experiences, and sense of humor proposed in a portion of the published studies. The relative weighting of these components may vary depending on the context or culture.

Figure 1.

Expert consensus

A panel of international experts on wisdom, who had published on this topic, completed anonymous surveys based on the Delphi or Rand Panel method.⁵¹ The study compared wisdom, intelligence, and spirituality on 53 items. The expert consensus was that while wisdom shared certain qualities with intelligence and spirituality, the three concepts were fundamentally distinct. The experts also agreed on the six core features of wisdom identified by the above-mentioned literature review.⁴⁹ There was a consensus that wisdom is uniquely human, driven by experience, is measurable and learned, and increases with age.

Wisdom in the Gita

The Bhagawad Gita or Gita is a 700-verse poem composed 500 years BC (summarizing much longer Yogas that date back several thousand years BC) and remains the religious and philosophical guide to wisdom in everyday life for millions of people. A mixed-methods qualitative-quantitative study of the Gita was undertaken to identify components of wisdom.²⁰ Specific search terms related to wisdom were used to identify relevant verses and categorize them into specific domains of wisdom. Overall, the Gita seemed to highlight five of the six components of wisdom found in our literature review⁴⁹ and expert consensus.⁴⁹ The main differences were lower emphasis on acceptance of uncertainty, and greater focus on religiosity/spirituality and lack of materialistic pursuits in the Gita.

Perspectives of Older Adults Near the End of Their Lives

Another source of definition of wisdom is the perspective of older persons near the end of their lives - a time when most persons describe a clarity about the most meaningful aspects of life.⁵² Semi-structured qualitative interviews of 21 patients (aged 58–97 years) in hospice care sought major components of wisdom and effects of the terminal illness on perspectives of wisdom⁵⁰. The subjects described the tension between accepting the situation (acknowledging uncertainty, regulating emotion, self-reflection, using sense of humor) and growing/changing personally in response to the situation (increasing openness to new experiences, adopting prosocial attitudes and behaviors, social decision making, exploring spirituality or religion.) The terminal illness motivated the urge to find and accept a balance between these two sides.

Multidimensional definition of wisdom

Wisdom is a multidimensional trait comprised of several specific components that are useful to the individual and to the society. However, the whole is greater than the sum of its parts, and the ultimate demonstration of wisdom is in behavior.

Measuring Wisdom

A requisite for good empirical studies of any construct is its optimal measurement. Subjective assessments form the core of evaluations of most psychological constructs including well-being, (perceived) stress, optimism and other personality traits. Our review of measures of wisdom published in peer-reviewed journals⁵³ found that the most widely used measures were self-rated scales.

Early Measures

Baltes, et al. used questionnaires, surveys, and interviews to develop the Berlin wisdom paradigm.^27,54–56 It viewed wisdom as a set of measurable skills, rating the respondent’s problem-solving and reasoning skills in response to scenarios such as “A 15-year-old girl wants to get married right away. What should she consider and do?” Trained raters scored the respondents’ ruminations according to the Berlin Paradigm’s five identified elements of wisdom (described above). A limitation of this Paradigm is its dependence on the raters’ interpretations, which could be biased, and a lack of consideration for emotion and pro-social behaviors in defining wisdom.

Other methods for assessing wisdom have included rating or nomination of (wise) peers, or nomination and characterization of famous wise people – usually Mother Teresa, Mahatma Gandhi, and Nelson Mandela. These methods also have limitations including a subject’s knowledge of the peer or celebrity as well as own biases.

Rating Scales

Two of the self-rated scales with good psychometric properties are Three-Dimensional Wisdom Scale (3D-WS)⁶ and Self-Assessed Wisdom Scale (SAWS).⁵⁷ The 3D-WS includes statements regarding the three dimensions of wisdom: cognitive, reflective, and affective. Respondents have to choose one of five options, from “strongly agree” to “strongly disagree” on statements such as “Ignorance is bliss” (cognitive), “I sometimes find it difficult to see things from another person’s point of view” (reflective), and “Sometimes I feel a real compassion for everyone” (affective). A limitation of the 3D-WS is its length (39 items). Recently an abbreviated 12-item version: the 3D-WS-12,¹⁰ was developed and found to be efficient and reliable. The 40-item SAWS⁵⁷ is based on five components: critical life experiences, reminiscence and life reflection, openness to experiences, emotional regulation, and humor. It uses a 6-point Likert scale from “strongly disagree” to “strongly agree.”

Thomas and colleagues recently developed San Diego Wisdom Scale (SD-WISE),⁵⁸ the first one to build upon a putative neurobiological model of wisdom described below. It assesses the six commonly identified wisdom components: social decision making, emotional regulation, pro-social behaviors, self-reflection, acceptance of uncertainty, and decisiveness. In the initial validation in 524 community-dwelling adults aged 25–104 years, the 24-item SD-WISE was found to be reliable, and demonstrated convergent and discriminant validity. The SD-WISE may be useful in both clinical practice and research settings.⁵⁸ Cloninger’s suggestion for integrating psychometric and neurobiological data to understand personality is applicable to wisdom as well.^59–61

Two papers examined a number of these wisdom rating scales systematically.^50,62 Gluck and colleagues compared four measures [SAWS, 3D-WS, Adult Self-Transcendence Inventory (ASTI),⁶³ and the Berlin Wisdom Paradigm] within a group of 47 persons nominated as wise by their peers and 123 control participants. While no one scale was superior, Gluck and colleagues emphasized careful selection of the appropriate scale for the theoretical concept (personal vs. general vs. other wisdom) and developed the Brief Wisdom Screening Scale, based on items most highly correlated to the common factor. Meanwhile, Bangen and colleagues reviewed nine instruments and found that while each had specific strengths and limitations, several had merits related to its broad usage (Berlin Wisdom paradigm), good psychometric properties (3D-WS), broad validity (Wisdom Development Scale,^64,65 SAWS), and real-world applicability (Reasoning about social conflicts.⁶⁶)

A common criticism of self-rated measures of positive characteristics is social desirability bias – i.e., participants may rate themselves more positively to present a favorable self-image. This bias has two potential sources: conscious manipulation of one’s image and subconscious belief in a positive self-image. Taylor et al. have reported that the problematic part of social desirability bias arises from conscious image management rather than from self-deception.⁶⁷ In the study of SD-WISE, an image management measure did not correlate with self-reported wisdom measures.⁵⁸

While objective measures seem to be desirable, self-reports have often been found to be valid, e.g., for quality of life which is subjective by definition. Similarly, self-rated general health is a significant predictor of morbidity and mortality.⁶⁸ In a national-level study of 1.3 million Americans, the correlation between subjective well-being of residents (based on census report) and objective measures of community wellness (including cost of living, wages, employment rates, crime rates, education spending, etc.) was surprisingly large (r = 0.6, p < 0.001).⁶⁹

Continuous observation of one’s behavior would seem desirable for assessing wisdom. However, aside from practical and ethical issues involved in recording people’s behavior, it is unclear who might be qualified to judge others’ behavior as wise or unwise.

In sum, all these methods have limitations. Eventually a multi-modal assessment would be needed.

Putative Model of Neurobiology of Wisdom

The observation that the basic concept of wisdom has not changed significantly from ancient periods (as exemplified in the Gita²⁰) to the present times suggests that it probably has an underlying neurobiological basis.⁷⁰ Early work on brain localization by Gall and Brodmann in the 19^th and early 20^th centuries, respectively, attempted to map different abilities to specific neuroanatomical regions.^71,72 Gall’s phrenology was ultimately deemed to be fraudulent, but Brodmann’s work was instrumental in numbering and assigning specific functions (e.g., motor, sensory) to specific parts of the cerebral cortex, now known as Brodmann areas. However, while motoric or sensory effects of stimulating or damaging certain brain regions can be discerned from animal studies, the areas responsible for wisdom or its components are far more difficult to pinpoint directly in animals or humans.

Meeks and Jeste reviewed the literature on neuroimaging, genetic, neurochemical, and neuropathological associations of each of the above mentioned six components of wisdom as well as conditions or behaviors reflecting a lack of these components (e.g., antisocial personality, impulsivity, dysregulated mood, or irrational acts). Specific “experiments of nature” were sought as well –case reports in which focal lesions in the brain, due to trauma or disease, resulted in loss of behaviors that characterize wisdom. The most famous case is that of Phineas Gage, a construction foreman in Vermont in the late 19^th century, who suffered a brain injury when an iron rod penetrated his skull and passed through the left frontal lobe, leaving the rest of his brain relatively unaffected.^73,74 Gage did not lose consciousness, retained his speech and motor abilities, and lived for another 12 years. However, there was a distinct change in personality from a disciplined, shrewd, and well-liked person to a profane, impulsive, and intemperate one. Other cases of “modern-day Phineas Gages”^75,76 have also reported localized brain damage in the prefrontal cortex (PFC) or limbic striatum causing behavioral changes indicating a loss of wisdom and a “precipitous decline in social and behavioral functioning.” Loss of wisdom has also been observed in fronto-temporal dementia (FTD), a dementia that is initially characterized by personality changes rather than memory loss, such as impulsivity, poor social awareness, disinhibition, antisocial behavior, and apathy.

The lateral PFC is activated during analytical processes, such as decision-making when choosing delayed rewards,^77,78 impulse control,⁷⁹ and understanding the perspectives of others.^80,81 The lateral PFC inhibits activity in the amygdala and ventral striatum; structures with roles in emotional responses and decision-making regarding immediate rewards.⁷⁸ Closely linked to the amygdala and ventrolateral PFC is the insular cortex or insula which is activated during moral decision-making in the face of uncertainty, empathy, emotional awareness and processing.^82,83 The lateral PFC has associated activity in the orbitofrontal cortex (OFC) and anterior and posterior cingulate cortices. The OFC is important for decision-making regarding delayed rewards, as lesions in this region are associated with impulsivity.^84,85 Activity in the anterior and posterior cingulate cortices has been associated with moral decision-making, recognizing moral dilemmas^86,87 social decision-making,⁷⁹ inhibition of prejudicial responses.^88,89 For more emotionally-linked wisdom components, the medial PFC and reward circuitry have prominent roles. The medial PFC is involved in prosocial attitudes and behaviors (as discerned from studies of “Theory of Mind” tasks,^90,91 social cooperation tasks,^92–95 and empathy studies^96–98) as well as in recognizing moral dilemmas and moral reasoning,^87,99 self-reflection,¹⁰⁰ and self-transcendental experiences.¹⁰¹ Similarly, the medial PFC are involved in emotion reappraisal, attenuating the amygdala response to negative and positive emotional experiences.^102–106 The reward is involved in social cooperation and altruism.^92–95,107 The fronto-parieto-temporal network has been highlighted in the spirituality literature. Prefrontal regions are activated during prayer¹⁰⁸ and meditation,¹⁰⁹ while the superior parietal lobes and temporo-parietal junction have less activation.¹¹⁰ Greater cortical thickness in the parietal lobes is associated with greater importance of spirituality.¹¹¹ Targeted stimulation studies have shown that inhibition of inferior parietal lobe activity results in increased spirituality.¹¹² Disturbed temporal lobe activity is associated with religious visions.^113,114 Mindfulness practices have been associated with the cortical midline structures (default mode network), insula and amygdala.¹¹⁵

Based on the totality of evidence, we have proposed a putative model of neurocircuitry subserving wisdom and its components (Figure 2).⁷⁰ This model posits that frontal areas including the lateral PFC (mainly dorsolateral PFC), together with the dorsal anterior cingulate cortex (ACC), and also the orbitofrontal cortex (OFC) and medial PFC inhibit or modulate brain regions involved in emotional processing and response (amygdala, ventral striatum, insula). These inhibitory effects may facilitate wisdom components such as social decision making, emotion regulation, acceptance of diverse value systems, and dealing effectively with uncertainty. Prosocial behaviors may be subserved by medial PFC, posterior cingulate cortex (PCC), insula, OFC, and reward neurocircuitry. Interaction and balance between the ancient brain regions of the limbic cortex and the more recently evolved PFC appear to promote components of wisdom.⁴⁹ It is worth noting that the PFC has been implicated in the neurobiology of character and the limbic striatum in temperament in studies of personality.^61,116 Spirituality appears to involve multiple brain regions – the PFC, bilateral parietal lobes, and temporal lobes – though the interactions between these have not been elucidated. This proposed model assumes normal brain functioning and the absence of dementia and other major brain disorders.

Figure 2.

Limitations of Proposed Neurobiology of Wisdom

The neurobiological model of wisdom presented here is based on an exploratory analysis of the published literature. Wisdom is a holistic complex multidimensional trait that likely involves several different neurocircuits, neural contexts, and brain regions, certainly beyond our current understanding of neuroanatomy and neurophysiology in regards to wisdom.¹¹⁷ Advances in neuroscience highlight the importance of understanding neural networks in such complex psychological traits and consideration of the dynamic system of the brain. However the reductionist approach is not completely discordant with the holistic concept of wisdom as such early work identifying regions of interest may be later integrated into neurocircuitry findings. The literature itself has limitations: varying definitions of wisdom components, discordance between experimental laboratory-based tasks and real-world situations, different sample sizes, varied neuroanatomical definitions, and individual heterogeneity in brain structure and function. The research literature will continue to evolve with improving technological approaches and increasing understanding of the biological processes underlying complex human traits.

Human Evolution, Longevity, and Wisdom

The average human lifespan in the US has increased from 47 years in 1900 to 80 years today and is expected to reach 90 by 2050, although there has not been a significant increase in fertility-span or health-span.^19,118 Thus, most people still have menopause or andropause at age 45–50, and physical strength also begins to decline around that age. Thus, most people now live for several decades after losing fertility. Another paradox of aging is that, despite increasing physical disability, self-reported well-being increases.^119,120 As people age, they appear to become happier, suggesting that other psychological factors, e.g., wisdom, must be contributing to greater wellness.

Several (but not all²⁷) studies have suggested that wisdom (or its components) increase with age.^66,121–123 For example, performance on the Theory of Mind tasks has been shown to be better in older than in younger adults.¹²⁴ Grossman and colleagues examined a large community sample aged 25+ years and found that, relative to younger adults, older adults had improved reasoning in regards to social conflicts and used higher-order reasoning schemes that reflected tolerance of other perspectives, awareness of one’s limitations, and facilitating compromise.⁶⁶ In a study of two groups of adults (60–84 versus 18–26 year old), Worthy reported that the older adults’ decision-making took into account long-term consequences and utilized their past experiences, while the younger adults made decisions that were more immediately gratifying.¹²² Several studies have also reported that, compared to younger adults, older individuals have better emotional regulation,^125,126 pro-social behaviors such as empathy and compassion,¹²⁷ subjective emotional well-being,^128,129 self-reflection or insight,¹²⁶ and ability to maintain positive relationships.^130,131 However, all these studies are cross-sectional, and point to a need for longitudinal studies to establish a link between wisdom and aging more directly.

Wisdom has been reported to be associated with better quality of life among older adults.^132,133 Ardelt’s work suggests that in older adults, personality and developmental traits have greater impact on well-being than objective factors such as physical health and socioeconomic factors.³⁴ Among older adults, wisdom was associated with better subjective well-being and life satisfaction, even when accounting for age, gender, race, marital status, physical health, socioeconomic status, financial situations, social involvement, and adversity.^34,134,135 Greater wisdom seemed to ameliorate the negative effects of adversity on well-being.^134,135 The correlation between wisdom and well-being was significantly stronger in older adults living in assisted care facilities or receiving hospice care compared to community-dwelling adults, and was mediated by a purpose in life and a sense of personal mastery.¹³⁶

Wisdom is useful not only for the individual himself/herself but also for other people including own offspring. In the mid-1950s, the biologist Williams first suggested a possible rationale for a long human life after menopause: the considerably higher “cost” of reproducing as women age may indicate that instead of expending energy on raising young children at that age, their efforts are better realized in aiding their adult offspring to reproduce.¹³⁷ This “Grandma Hypothesis”¹³⁸ posits that post-reproductive women may compensate for lost fertility by caring for their grandchildren, thus reducing the child-rearing burden on their own offspring. This allows their children to reproduce earlier, more frequently, and more successfully. Evidence for the Grandma Hypothesis comes from animal¹⁹ and human studies. Orca whales, who form multigenerational pods, have significantly increased mortality risk of offspring (up to five-fold in daughters and 14-fold in sons) after the death of a post-reproductive female whale in the pod.¹³⁹ Similarly, the presence of grandmothers in Asian elephant herds increases rates of reproduction and calf survival.¹⁴⁰ Grandmothers aid directly in rearing offspring, as illustrated in Seychelles warblers where post-reproductive females help the breeding pair feed chicks¹⁴¹ and bottlenose dolphins who nurse their grand-offspring.¹⁴²

The anthropologist Hawkes reported a similar phenomenon in extant hunter-gatherer societies. Within the Hadza, a Tanzanian hunter-gathering society, involvement of grandmother helpers increase longevity of the grandchildren.¹⁴³ Similarly, in modern societies, when grandparents are involved in the raising of grandchildren, the grandchildren have better outcomes: fewer emotional problems, fewer adjustment difficulties, and more pro-social behaviors.¹⁴⁴ Similarly, findings from 127 multigenerational households (children, parents, grandparents) studied by Conger and colleagues in the Family Transitions Project¹⁴⁵ showed that grandchildren with greater grandmother involvement had fewer behavioral problems. A multi-generational study of 2,800 Canadian and Finnish women born before 1900 reported that the children of older mothers had better reproductive outcomes—having their own children earlier, more frequently and more successfully.¹⁴⁶

The ability of grandparents to care for grandchildren are negatively impacted by age-related disease including neurodegenerative disorders (i.e., Alzheimer’s disease) and cardiovascular disease. Thus, decreased vulnerability to such illnesses may confer evolutionary advantages, even on the gene-level. Varki and co-authors¹⁴⁷ found that a variant of CD33 that suppresses the accumulation of amyloid beta peptide in the brain, was four-fold more common in humans than in chimpanzees, one of our most genetically similar relatives. Similarly, while the APOE4 allele is a known risk factor for Alzheimer’s and cerebrovascular diseases, the APOE2 and APOE3 alleles appear to confer lower risk of dementia and are more prevalent in humans. These derived protective alleles, dubbed the “grandparent genes,” may have evolved to protect against neurodegeneration and cerebrovascular disease in order to maximize the contributions of postproductive “wise” individuals to the raising of their kin.¹⁴⁷

Wisdom-Related Neuroplasticity of Aging

The development of wisdom over the lifespan has been challenging to study. The current evidence is neither data-based nor longitudinal. Though prospective longitudinal studies are lacking, there is evidence of the potential to gain wisdom with age. Though life experiences appear to play a role, they are not sufficient to increase wisdom. Erikson’s theory defined wisdom as the final psychosocial conflict of the lifespan, as older adults reflect on their lives.¹⁴⁸ Sternberg¹⁴⁹ hypothesized several connections between aging and wisdom: increased wisdom after a spiritual awakening, increased wisdom during adolescence in tandem with increased fluid intelligence, increased wisdom throughout life in tandem with accumulated knowledge over the lifetime, initial increase and later plateau of wisdom in tandem with the changes in fluid and crystallized intelligence over the lifetime, and decreased wisdom with age due to loss of epistemic wisdom (self-centered overconfidence or self-defeating loss of wisdom.) Trajectories of wisdom likely vary for each individual, accumulating wisdom from personal experiences and relationships.^29,150 Ardelt acknowledges that while aging may not inherently increase wisdom, wise persons tend to be older due to the amount of time required to accumulate wisdom.¹⁵¹

Though aging is generally associated with progressive cognitive dysfunction, the effect is not homogenous. With appropriate physical, cognitive, and psychosocial stimulation; brains continue to evolve even in later life, suggesting neuroplasticity of aging. Gage and colleagues have reported that physical activity and psychosocial stimulation in old mice lead to increased synaptic connections, cerebrovascular growth as well as neurogenesis in the dentate gyrus of the hippocampus and periventricular region.¹⁵² These findings have been replicated in other animal species.^153,154 Such processes may serve to compensate for age-related brain degeneration in humans.^155,156

There is evidence of compensatory phenomena to neutralize or overcome the deleterious effects of aging-associated neurodegenerative changes in people who are active. A review of 50 studies of structural brain imaging and cognitive aging¹⁵⁷ showed an association of successful cognitive aging with larger structures and greater connectivity in the brain, notably in the PFC and medial temporal lobe. To compensate for aging processes in the brain that result in a loss of synapses and neurons, more neuronal networks may need to be involved in performing a mental activity in older than in younger adults¹⁵⁸. Active older adults’ brains are less likely to show atrophic changes than sedentary, lonely, inactive seniors’.^{157,159–161} Hemispheric Asymmetry Reduction in OLDer adults (HAROLD) refers to increased activity in the contralateral brain region and decreased lateralization in older adults¹⁶². By engaging more of the brain, an active older adult may be able to do as well as a younger person in cognitive tasks, such as learning new things. In terms of specific enhancement of the activity of frontal and prefrontal cortex, studies suggest a Posterior Anterior Shift with Aging (PASA) reflecting decreased activity in the posterior regions and increased activity in the anterior brain regions in older adults^163,164.

Aging is also associated with a change in emotional responsivity. Carstensen, et al. showed that in older age, with a growing awareness of the limited time left, people worry less about the future and report greater personal satisfaction in past experiences.^129,165,166 This “socioemotional selectivity” theory highlights the importance of emotional goals as the time horizon shrinks. Similarly, a study of brain scans and other tests of emotional activity demonstrated reduced “regret responsiveness” in older healthy participants compared to younger adults.¹²⁶ The older adults reported greater ability to dispel feelings of disappointment and remorse, and overall less concern about things they could not change. On the other hand, older individuals have increased emotional positivity, as the aging amygdala becomes less responsive to stressful images and negative emotions on functional imaging studies^167,168, brain activation in response to negative emotional stimuli, regret, and fear is decreased¹²⁶, and dopaminergic activity in the reward circuitry is reduced¹⁶⁹. There is also less functional connectivity between the amygdala and the hippocampus, but increased connectivity between the amygdala and dorsolateral prefrontal cortex, which may effectively reduce negative memories while enhancing positive ones.^167,168

Wisdom-related Interventions

Can wisdom be increased? This is an important question that deserves to be investigated empirically. There are several reasons for supporting the concept that wisdom is modifiable. Other traits such as resilience and optimism have been found to be moderately heritable (with estimates of 33% to 52%¹⁷⁰) suggesting that they can be influenced by environmental factors to a significant extent. While heritability of wisdom is unstudied, it may be similar to that of other personality traits. Several recent studies have reported increase in resilience and optimism with behavioral interventions.^171–175 While acknowledging limitations of these clinical trials, it seems that such traits can be improved through psychotherapeutic techniques. Importantly, if wisdom can be markedly impaired by specifically located brain trauma or diseases such as FTD, as discussed above, it should be theoretically possible to enhance it through interventions that enhance the functioning of those brain regions through biological or behavioral techniques. Moreover, deficits in wisdom may be global [e.g., frontotemporal dementia (FTD) and impaired judgment, prosocial behaviors, empathy] or targeted (e.g., autism and social cognition.) The wisdom components overlap and are interrelated; improving one component of wisdom may improve others. Though interventions targeting one wisdom component may be easier to execute, multicomponent interventions of wisdom may confer greater overall benefit, similar to combining exercise and diet interventions for greater weight loss.

Jeste and colleagues conducted a systematic review of randomized controlled trials or RCTs, chosen by surveying the MEDLINE and PsycINFO online databases.¹⁷⁶ The search identified interventions targeting compassion and empathy, emotional regulation, spirituality, openness to new experience, and one study to increase wisdom as a whole. A majority of studies were conducted in adult participants, including a few in adults over age 60. While some interventions were conducted in community participants (e.g., elementary or middle school students, bullies in schools, couples in long-term relationships), several interventions involved subjects with mental illnesses such as depression, anxiety disorders, personality disorders, or physical illnesses such as breast cancer and cardiovascular disease.

We only found two published interventions that improved wisdom as a whole – one RCT and one non-randomized trial. The RCT was an illustrative cross-over study examining life review therapy in older veterans with PTSD,¹⁷⁷ which reported increased wisdom (SAWS) with the life review therapy. The non-randomized spirituality intervention¹⁷⁸ involved group discussions of biblical passages and applications to contemporary situations and reported increased self-rated wisdom (Wise Thinking and Acting Questionnaire).

A number of interventions focused on specific components of wisdom. An RCT in patients with binge eating disorder found that a 3-week self-compassion training and food planning intervention was significantly associated with improved eating disorder pathology and self-compassion compared to a food planning/behavioral strategies intervention and a wait-list control condition.¹⁷⁹ One of the most interesting studies was an RCT of empathy and compassion training and a memory intervention control group in young adult women. It used an fMRI socio-affective video task to analyze the effects on activation of relevant brain regions. The training intervention significantly increased empathy and compassion on validated rating scales. Additionally, it enhanced brain activation in anterior insula and anterior midcingulate cortex, regions associated with empathy regarding pain, as well as in ventral striatum, anterior cingulate, and medial orbitofrontal cortex – regions identified in our putative wisdom neurocircuit.¹⁸⁰

Several limitations of the intervention literature must be noted. The information on study participants’ characteristics, theoretical basis underlying the intervention, trial methodology, outcomes evaluated, and statistics employed, was variable. Longer-term efficacy of the interventions is not known. Only one RCT and one non-randomized pilot study used a scale for wisdom as an outcome measure¹⁷⁷; all others focused on individual components of wisdom. Notwithstanding these limitations, the review of wisdom-related interventions does suggest that it is possible to improve certain components of wisdom in at least subgroups of subjects with or without mental or physical illnesses. Approximately half of the RCTs reported significant improvements in the primary outcome measures and well-being with medium to large effect size. Thus, well chosen interventions have the potential to improve the well-being of persons with psychiatric disorders (especially for interventions involving prosocial behavior and emotional regulation training) or physical illnesses (particularly for enhancing spirituality in illnesses such as cancer or as a component of palliative/hospice care) by enhancing wisdom components. Interventions that aim to improve overall wisdom should address multiple components and include outcomes related to mental and physical well-being. Clinically, such interventions have great relevance to brain disorders that lead to general loss of wisdom (e.g., FTD, brain injuries). Many clinical challenges associated with these illnesses are related to problems like impulsivity, lack of empathy, and difficulty with emotional regulation. Current medication-based therapies for mood lability and impulsivity are limited by undesirable side effects and inconsistent efficacy. Behavioral interventions to improve these problems would greatly benefit this clinical population. Furthermore, the general population of all ages would benefit from increased wisdom and/or components of wisdom as they navigate difficult situations in their everyday lives.

Carefully designed trials targeting wisdom as a contributor to overall health would be useful. Larger, hypothesis-driven RCTs with appropriately selected control groups, using validated outcome measures, and examining other health-related and biological measures are recommended. Technological tools such as biofeedback or virtual reality may be used to facilitate interventions. Finally family-, group-, and community-level interventions should be considered.

Suggested Model of Development of Wisdom

Similar to the complex gene × environment interactions that have been postulated in the development of resilience,¹⁸¹ we propose a model of development of wisdom that draws from the genetic, epigenetic and environmental influences (Figure 3.) Specific genes (i.e., grandparent genes and others associated with positive psychological traits and wisdom components) may increase the propensity for wisdom. A pro-wisdom environment, either through a supportive family (i.e., the Grandma Hypothesis) or societal structure, influences an individual’s development of pro-social behaviors, emotional regulation, self-reflection, spirituality, and other wisdom components. The genetic and environmental influences are further modulated by changes associated with aging. Epigenetic changes are triggered by life events that range from different types of adversities to physical, cognitive, and social stimulation. Similarly, aging affects both brain structures and connections of and within the wisdom neurobiology with outside structures such as the hippocampus. Aging of the brain in an active older person may be associated with PASA and HAROLD mechanisms described above as well as reduced amygdala responsiveness to negative or stressful stimuli. All of these influences may contribute to stronger and more balanced functioning of dorsolateral and ventromedial prefrontal cortex and limbic striatrum, leading to greater wisdom with both individual- and societal-level benefits. Such benefits then feedback to sustain pro-wisdom genes and environments.

Figure 3.

Implications and Recommendations

Increased wisdom with aging provides at least a partial answer to two major paradoxes of aging: why humans survive for decades after their fertility period ends and why older people are happier than younger ones. Wisdom benefits both the individual and the society as a whole. Increased wisdom in older individuals enables them to flourish in later life while the grandparents improve species survival (Grandma Hypothesis) and also impart wisdom to younger generations.

Future wisdom research has several potential applications and directions.

1. Wisdom has important associations with mental health and well-being. Future work should investigate the relationship of wisdom to physical health, including biomarkers of aging.

2. Wisdom has relevance to neuropsychiatric disorders that impact judgment and personality, such as FTD or frontal lobe injuries and tumors. Research on “personality rehabilitation” (comparable to physical or cognitive rehabilitation) to address this loss of wisdom would have public health significance.

3. Younger people report worse mental health compared to older individuals.^{120,130,131,167,182,183} Furthermore, research in the past 30 years has suggested that mental illnesses may be becoming more prevalent in youth but less common in older adults, attributed to declining incidence, better rates of recovery, and healthy survivor bias.^184,185 Intergenerational activities such as the Baltimore Experience Corps that recruited older community-dwelling adults to serve as volunteer mentors and tutors in elementary schools, have been shown to improve outcomes for both the children (whose grades rose along with mental health) and the older adults involved.^186–188 Older participants not only had greater well-being, happiness, and purpose in life, but also increased cortical and hippocampal volumes at 2-year follow-up compared to the control group.¹⁸⁶ Research is warranted on bio-psycho-social effects, including formal assessment of wisdom and its components, in both youth and older adults participating in different levels of intergenerational programs.

4. The educational system has traditionally valued intelligence and academic skills,¹⁸⁹ but these do not necessarily translate to increasing wisdom (i.e., emotional regulation, prosocial behaviors) or ensure greater well-being. The need for teaching wisdom of life extends to graduate and professional education, including medical school. High rates of burnout, depression, and suicide among medical students and physicians have been attributed, in part, to intense work stress, and warrant a greater focus on well-being and happiness.^190–193 The educational system would be an attractive venue to try to systematically increase wisdom, and thus well-being, to benefit both individuals and societies. Standardized assessments are critical to demonstrate effectiveness of such programs.

5. Further elucidating the biological mechanisms underlying wisdom could identify possible biomarkers of wisdom, e.g., neuroimaging markers of greater or reduced activity of specific brain regions in response to selected tasks.

6. Development and testing of wisdom-enhancing interventions should be a key research area.

In conclusion, there is a need to expand empirical research on wisdom, given its immense but largely untapped potential for enhancing mental health of individuals and promoting well-being of the society at large.