The Broader Autism Phenotype Constellations–Disability Matrix Paradigm: theoretical model for autism and the broader autism phenotype

Abstract

The prevalence of autism has increased dramatically over the last 60 years, and the cause of this increase is unclear. In this paradigm-shift paper, I propose an explanatory paradigm for the cause of autism and its increased prevalence in the general population. I also discuss how social and historical contexts may have influenced the evolution and manifestation of specific traits in the autism population. These traits expand the characterization of the broader autism phenotype to include a constellation of socially valued traits, termed Broader Autism Phenotype Constellations (BAPCO). The frequency of these traits may have increased due to assortative mating opportunities that occurred alongside social changes in education and occupational opportunities over the last 100 years. I propose that assortative mating can lead to both positive and negative developmental consequences affecting social and language development. I also propose that BAPCO traits, which are not intrinsically disabilities, could interact with co-occurring conditions in a new model called the BAPCO-Disability Matrix Paradigm (BAPCO-DMAP). In this paradigm, autism is located at the intersection of BAPCO traits and at least one co-occurring condition. These proposed models support the need to create a more comprehensive definition of autism that includes constellations of BAPCO traits. The BAPCO-DMAP paves the way to testable predictions of autism prevalence and provides a framework to better understand the foundational traits of autism. Finally, this paradigm radically redefines the broader autism phenotype with characteristics that can inform therapy and child development.

INTRODUCTION

Over the last 60 years, the prevalence of autism has increased dramatically. The reason for this increase is unknown, even after controlling for changes in defining diagnostic characteristics, diagnostic substitution, and increased awareness. Autism is defined as deficits, differences, and delays in social-communication skills coupled with restricted interests and behaviors [1]. The phenotypic expression of these and other characteristics in this population are extremely heterogeneous [2]. This heterogeneity is also largely unexplained. Although autism is highly heritable and several genes predict the condition, the causes of autism are still controversial. Currently, there is no unifying paradigm to explain the nature of autism and its increased prevalence.

This paradigm-shift paper describes how social and historical contexts may have influenced the mechanisms of evolution and developmental plasticity of specific traits in the autism population. This paper also proposes a theoretical paradigm for the cause of autism and its increased prevalence in the general population.

Autism and genetics

While the causes of autism are unknown, the etiopathogenesis of the condition involves a complex interaction between genes and the environment [3]. Autism is highly heritable. Among monozygotic (identical) twins, the concordance rate is 98%. Among dizygotic (fraternal) twins, the concordance rate is between 67% for those with an autism diagnosis and 53% for those with the broader autism phenotype (BAP), as currently defined [4].

The genetic factors that contribute to autism range from monogenic to polygenic. Monogenic factors are single genes that are highly predictive of an autism diagnosis. These factors are often due to a de novo mutation or rare inherited genes. De novo structural variants, including rare inherited gene variants, account for up to 30% of autistic¹ individuals and are associated with low nonverbal IQ [6]. However, while de novo variants may contribute to or predict autism, they do not necessarily cause the condition. In fact, no gene or genetic condition results in all carriers manifesting symptoms of autism². Even genes with the strongest relationship to autism can be expressed by individuals who do not meet the criteria for autism. For example, while 60% of males with Fragile X syndrome meet the criteria for autism, the remaining 40% do not [9]. Thus, the presence of Fragile X syndrome is highly predicative of autism, but not a definitive cause of the condition.

Autism is primarily inherited via common genetic variants, or single nucleotide polymorphisms which are the most common gene variation in people [10]. A range of single nucleotide polymorphisms are predictive of an autism diagnosis, albeit with very small effect sizes [6]. However, when an individual presents with multiple SNPs that predict autism, these genes cluster, act in concert, and cumulatively become more predictive of autism and other disorders [6]. Research on these SNP clusters, or polygenetic factors, is growing. This research may uncover thousands more common genes with small, and potentially additive, predictive properties for autism [6]. The collective risk of these SNPs in contributing to specific outcomes is summarized by the polygenetic risk score. In contrast to other developmental disabilities, the polygenetic risk score for autism correlates with higher educational attainment and IQ [6].

Finally, multiple environmental factors may contribute to autistic development and individual genetic vulnerability [3]. These environmental factors include maternal and paternal age, health and nutrition, environmental toxins and pathogens, illness, and prenatal or postnatal trauma [3]. Despite this link, studies of twins indicated that genes underlie most variance in autism and are a stronger contributor than environmental factors [4].

Rising prevalence of autism

Over the past 60 years, the prevalence of autism has increased steadily and dramatically [11,12]. In the United States, the prevalence of adult autism grew from 1 in 2,000 (0.05%) in 1960 [11] to 1 in 58 (2%) in 2020 [12,13]. Multiple hypotheses may explain this increased prevalence, including changes in the defining diagnostic characteristics, diagnostic substitution (where a different diagnosis would have been given), and increased awareness. However, in a cohort study of births in California, researchers found that these factors accounted for, at most, only half of the increased prevalence of autism in California [14,15]. While researchers also examined other factors, including the role of genes and the environment, there is no consensus regarding the mechanism(s) underlying the increased prevalence.

RECONCEPTUALIZING THE BROADER AUTISM PHENOTYPE

Autism is traditionally defined as deficits, deviance, and delays in social and communication development. The condition is also characterized by skills coupled with restricted intense interests and/or repetitive behaviors [1]. Traditionally, the BAP includes milder symptoms of autism. In a systematic review, Rubenstein and Chawla summarize that BAP traits include pragmatic difficulties, broadly defined communication difficulties, poor social skills, rigidity, broadly defined stereotyped behaviors, impaired social emotional recognition, and aloofness [15]. These traits infer that the key signs of the BAP are related to differences, deficits, and delays in social interaction and communication, as well as a propensity for intense, rigid, and/or repetitive thoughts and behavior. While these traits can certainly co-occur, they may not be necessary elements or key traits of the BAP.

I posit that the BAP primarily consists of clusters, or Broader Autism Phenotype Constellations (BAPCO), of common traits that are not necessarily related to social or communication challenges (Fig. 1).

Fig. 1.

Primary traits of the Broader Autism Phenotype Constellations. Individuals will have variable numbers and intensities of traits within their own constellation.

I hypothesize that a concentration of certain non-disabling traits can interfere with developmental timing, and that the traits can interact with the developmental timing of other disabilities. I also propose to expand the characterization of the BAP to include a constellation of socially valued traits. Figure 2 shows the social-biological evolution model of the BAPCO.

Fig. 2.

The social-biological evolution model of the Broader Autism Phenotype Constellation traits and autism. In this model, the historic changes in educational and occupational opportunities for men and women created opportunities for assortative mating on traits related to the BAPCO. This mating has produced children who fit these BAPCO traits. Individuals may also choose to engage in assortative mating on non-BAPCO traits. When assortative mating selects on BAPCO traits, offspring who have extreme BAPCO traits and/or a developmental disability are classified as having autism. When assortative mating selects on non-BAPCO traits, offspring with a developmental disability are classified as having the specific developmental disability. BAPCO, Broader Autism Phenotype Constellation.

BAPCO AND ASSORTATIVE MATING

Across cultures, humans show candidate traits of the BAPCO, such as memory, attention, focus on object relations, systemizing, sensory exploration and sensitivity, and non-conformity. The parameters of these traits are influenced by several mechanisms that change the frequency of a trait within a population. These mechanisms include genetic drift, de novo mutations, and natural selection, as discussed previously. The mechanisms also includes assortative, or non-random, mating [16].

Assortative mating and salience of traits

Positive assortative mating is a form of non-random mate selection that occurs when individuals in a population mate with others who have a similar phenotype. This form of mating depends heavily on the salience of the similar traits. If individuals cannot detect similarities, they cannot engage in positive assortative mating.

For humans, cultural environments can increase or decrease the salience of particular phenotypic traits of individuals. Also, the ability to engage in positive assortative mating depends on the ability (or freedom) to select mates based on these salient characteristics³.

Assortative mating and trait constellations

Assortative mating can change the frequency of traits in the population. For example, the frequency of traits will remain stable or increase slowly if only one sex of the population selects similar traits. However, if both sexes can select for specific traits, then the frequency—and sometimes intensity—can increase at an exponential rate within the population.

Assortative mating of highly represented traits in subgroups of human cultures may positively and negatively impact the development of offspring. Such an impact has been shown with other species, namely dogs. Most characteristics found among domestic dogs, including body size, follow a normal distribution. However, dog breeds have been developed by pairing dogs with similar traits, such as two large dogs or two small dogs. This pairing can produce offspring that are as large or as small as their parents and, potentially, larger or smaller than their parents. Thus, these traits become intensified. While these intensified traits can have some advantages, such as for hunting or companionship, they can also have disadvantages. For example, Great Danes were bred to be giant dogs; however, they are highly susceptible to heart problems and have a shorter lifespan [17]. Also, Italian Greyhounds (and other toy dogs) who were bred to be tiny house pets have thin legs that are more prone to fractures than their derivative Greyhound and Whippet breeds [18].

In addition to trait intensity, whole clusters of traits can be represented in a subgroup. This effect can also be seen with dog breeding. For example, Chihuahuas and Border Collies have different sizes, temperaments, and abilities. Chihuahuas tend to have high energy and alertness, and they often form strong bonds with one person [19]. These traits make them suitable house or apartment pets but not herding dogs. On the other hand, Border Collies were bred to herd [20], and they are naturally athletic, playful, and require rigorous physical exercise and mental stimulation. When deprived of physical and mental stimulation, Border Collies are likely to engage in destructive behaviors, such as chewing and/or scraping furniture and building structures. Thus, Border Collies have sets of traits that make them suitable working dogs but not house or apartment pets.

Assortative mating may increase the frequency and intensity of BAPCO traits in humans, much like that seen in dog breeding. However, there is a key difference between these two models: dog breeding is planned by external drivers (eg, humans choosing the traits they want in dogs), whereas assortative mating in human populations is determined by internal drivers (eg, individual preferences). These individual preferences can be affected by environmental pressures that impact decisions for mate selection. For humans, these pressures can include historical social pressures that increase the salience and value of traits available for mate selection in the general population.

BAPCO AND AUTISM PREVALENCE

Although the prevalence of many neurodevelopmental disorders decreases with higher socioeconomic status (SES), this decrease is not found with autism. Earlier studies suggested an increase in prevalence with higher SES. However, current studies showed that the prevalence for autism without a co-occurring intellectual disability increases with SES. No such association was found for individuals with autism and a co-occurring intellectual disability. For a review of SES and neurologic disorders in children, see [21].

Individuals who represent the constellations of traits related to the BAP have likely existed since the beginning of human civilization. Yet, the prevalence of BAPCO in the population of higher income countries may have increased due to compulsory primary and secondary education with merit promotion of both males and females. The dramatic increase in this prevalence in recent years may also be due to more women joining the workforce and pursuing higher education.

BAPCO and social factors

Over the last 100 years, higher income countries have undergone tremendous social changes. In the United States, public education for elementary grades became compulsory beginning in 1918 [21], and access to high school education became more universally available in the mid-1940s [22]. Early on, public education in the United States relied on social factors (eg, age) for promotion from grade to grade. However, over time, school systems shifted to rely more on merit (eg, demonstrating a pre-specified minimum level of knowledge or skills) than social promotion [23].

Merit promotion in the US education system may strongly select for specific skills for advancement. These skills include higher attention and memory, as well as the ability to engage in a variety of cognitive skills (eg, logic, abstract thinking, flexible thinking). Thus, individuals with strong skills in attention, memory, and cognitive processes may be more valued by academic systems and more successful in attaining education.

Additionally, individuals can exercise, to greater and lesser extents based on a variety of social factors, preferences in work and career choices. Loosely speaking, over the last 100 years, individuals have experienced greater freedom to choose their occupation than previous generations who were more limited by social class and paternal occupations. In other words, the son of a shoemaker is not destined to become a shoemaker but, instead, has more opportunities to pursue a wide range of work and career pathways. To the extent that individuals can choose career pathways, their choices represent a salient manifestation of phenotypic characteristics, such as ability and preferences. In this way, people who choose to become entertainers have different phenotypic traits than those who choose to become engineers. Similarly, people who choose to engage in data entry may have different phenotypic traits than those who choose to work in the restaurant industry.

Our opportunities and choices affect where we live and work, what hobbies or recreational activities we engage in, with whom we socialize, and with whom we have offspring. Furthermore, the influence of education, occupation, and personality on personal choices can create social communities, or subpopulations, of individuals with similar traits. These subpopulations, due to both social conditions and personal preferences, have stronger representations of some phenotypic traits over others. When people with similar traits procreate (as in assortative mating), their offspring can present with an increased frequency and intensity of traits represented in these subpopulations. Based on this model, individuals who succeed in academic and occupational settings and who select mates based on traits related to the BAPCO (and environmental proximity) are more likely to have children with the BAPCO traits.

BAPCO and advances by women

Since Kanner and Asperger first identified children with characteristics of autism, the prevalence of autism has steadily increased [13]. The educational and occupational advances of women may have contributed to the increase of BAPCO in the population.

Historically, societal expectations in the United States held that women should marry and perform domestic services as their primary vocation, while men were relatively free to pursue a wider range of occupations and skills. This expectation limited the number of phenotypic traits that men could select from among women (although women could still choose among the wider range of educational and occupational traits expressed by men). However, as access to opportunities for education and occupational choices increased for women, both men and women could mutually select for traits expressed through education and occupational choices. This process of mutual assortative selection based on educational and occupational traits could result in an even greater prevalence of BAPCO than occurred before 1930.

BAPCO AND CHILD DEVELOPMENT

Autistic traits can have positive or negative effects on child development. For example, memory and attention are generally regarded as positive. But when they are intensified enough, they could challenge the development of important skills.

Object orientation in communication and social development

Not all children with autism experience speech delays or echolalia. However, attributes that define the development of autism include differences and delays in social and communication skills, as well as object orientation, or a preference for orienting to objects over social stimuli. Indeed, Sung and colleagues studied social motivation and intense interests using the Broader Phenotype Autism Symptoms Scale [47]. They found that the highest heritability of language onset, expressiveness, and conversational skills occurred in multiplex families with autism (biologically related, nuclear families with at least two children with autism).

On average, children and adults on the autism spectrum prefer non-social stimuli over social stimuli more than individuals without autism [48] or with disabilities such as Down Syndrome [49] and schizophrenia [50]. Based on this preference, researchers developed the social motivation hypothesis. This hypothesis characterizes autism by a reduced social reward system that affects how autistic individuals attend to and learn from their environments. Essentially, the less attention an individual gives to social stimuli in their environments, the less they will be able to collect and process social information (illustrated by a bell curve in Fig. 3). This relationship leads to developmental delays, deficits, and differences in social and communication skills [24,25].

Fig. 3.

Bipolar model of social and object orientations of attention. This model assumes that attention preference between social and object information is bipolar. The model also assumes a natural distribution of social-object orientation preferences, with most individuals embodying moderate preferences of both object and social orientation. Individuals who devote more attention to objects and object information in the environment necessarily devote less attention to people and social information in the environment (and vice versa). As such, individuals whose attention preferences are closer to either tail of this distribution would likely demonstrate deficits in skills sets that require greater attention and learning in the less preferred side of the attention spectrum.

Within the BAPCO, an increase in object orientation is not inherently a disability. Such attention differences may be beneficial for certain occupations that require the preference to orient to non-social stimuli over social stimuli for long periods of time (eg, art, music, science). For example, previous research showed higher relationships between the BAP and males, individuals interested in the hard sciences, and individuals with at least one parent in a science field [26]. Because some societies value certain occupations, members of these societies may value specific traits in their mate selections. While the difference in attention preference could build specialized skills in non-social or less social domains, it may also hinder development in social and language domains (as compared with more socially oriented individuals). This hindrance can be even stronger as an individual moves toward the tail-end of the distribution for object orientation.

Attention and memory in language development

Infants learn language during a critical developmental period and in a manner that differs from older children and adults. Infants can better distinguish between the sounds produced in any language, and they can learn the words of their native language without being explicitly taught (unlike adult learners) [27].

Spoken languages among humans comprise phonemes, the smallest and most basic unit of language sounds [27]. Infants use probabilistic learning to determine which combinations of these sounds constitute words in a language [28]. For example, the phrase “pretty baby” has four phonemes: “pre,” “ty,” “ba,” “by.” Infants use statistical probabilities to parse the words “pretty baby” because, in English, the sound “ba” is more likely to be followed by “by” than “ty” (see [30] for a more in-depth description of these mechanisms).

These learning processes are governed by cognitive and physical abilities, as well as the constraints on these systems. Interestingly, constraints may accentuate learning abilities [29]. According to constraint theories, infant cognitions (eg, attention and working memory) are limited. Thus, the infant may focus on the phonemes instead of the whole word or phrases that they hear. In contrast, adults who have higher working memories and greater attention spans can focus on larger segments, or chunks, of information. In this way, an adult can attend to the whole chunk of “pretty baby” instead of the individual phonemes within the words. The increased attention and memory associated with chunking allows children and adults to learn and use complex information, such as phrases, grammar rules, and lexicons [30]. MacWhinney and Anderson describe how information processing theory accounts for the timing and types of grammatical errors that children make [32].

An infant’s short memory and attention allow them to learn the basic components (and their corresponding probabilistic frequencies) of language, which forms the foundations needed for fluency in their native language. However, if an infant’s parameters for attention and memory were larger than average, then the infant might experience impairments in identifying the phonemes and their corresponding probabilities. Such an impairment is similar to adults who are learning a second language. Even if the infant could chunk larger sounds together, they would not have the physical development needed to mimic these larger chunks.

To identify words before chunking together whole phrases, infants need the typical serial order of linguistic information processing to distinguish phoneme sounds and probability of phoneme order. Without this process, infants with increased memory and attention would be prone to chunking but without the experience of knowing a previous language. A similar effect might occur with second language learners without other cognitive abilities (eg, logic, reason) and experiences needed to parse the language. These difficulties could create a language delay. As an infant with increased memory and attention develops into childhood, a language delay could transform into echolalia in which the child uses whole, unparsed (“babbling”) phrases. Such a child may use whole phrases instead of words because the words might not yet be parsed. For example, when a parent asks a child with autism, “Do you want a cookie?” and the child repeats the question, the child might not be reversing the pronoun. Instead they interpret the entire phrase to mean “cookie.”

The process of chunking whole phrases would make understanding which whole phrases should receive a “yes” or “no” response quite difficult. The challenge would be even greater when parsing the language to use words and sentences flexibly. A child with this difficulty might engage in sense-making activities, such as watching shows repeatedly to search for language patterns. This child might appear to recite entire sections of language without true understanding. In this case, language learning for autistic children with language delays should be approached as if they are learning a second language. This approach would emphasize breaking language meanings into smaller meaningful segments with a high emphasis on probabilistic repetition. Interestingly, many children on the autism spectrum seem to pursue such information repetition but, on their own, they cannot limit the information segments to sizes that would facilitate their language development.

Other traits identified in the research literature encompass preferences and aversions that may affect offspring development. These traits include systemizing [31]; pattern, picture/visual, and verbal thinking [32]; sensory reactivity [33]; attention to detail [34]; and tendencies toward harm avoidance, persistence, and a methodical approach to activities [35]. The literature is filled with research on differences between groups of individuals with and without autism across these and other traits. Yet, no single individual on the autism spectrum presents with all these traits, and some will show strengths in traits that are uncommon in autism. For example, while individuals with autism tend to be higher in systemizing and lower in empathizing, some show a balance of these traits [2]. Similarly, Parents of autistic individuals show variation on these traits.

Systemizing traits are commonly found in specific occupations, such as technical fields in science, health care, engineering, computer programming, and finance [36,37]. Also, students identified with autism in special education who pursued science, technology, engineering, and mathematics (STEM) fields were more likely to transfer from two-year to four-year colleges than those who pursued non-STEM fields [38]. However, while all science fields require the trait of systemizing, they may not all be equally tolerant of many BAPCO or autism constellations. Even fields that focus on the value of social skills (eg, business and psychology) require scientists who demonstrate high levels of systemizing or analysis. However, if individuals with BAPCO or autism appear to lack the fluid social skills valued by these fields, they may face barriers in obtaining successful careers in science.

CONCEPTUALIZING BAPCO CONSTELLATIONS

Despite the potential career limitations, some autistic individuals succeed, and even excel, as actors, careers that arguably require high social skills. For example, Sir Anthony Hopkins describes using systemizing skills to “deconstruct, to pull a character apart, to work out what makes them tick” [39]. In essence, he uses systemizing to build empathy. He is also well known for having a remarkable ability to memorize—he recited a seven-page courtroom speech in a single take. Sir Hopkins demonstrates systemizing, high attention and memory, and a strong verbal/lexical interest combined with some level of intense social orientation (Fig. 4). The timing and nature of this alternative autistic approach to social orientation may vary from the typical developmental pattern of social development. Yet, the outcome of his development and experiences are socially valuable.

Fig. 4.

Examples of BAPCO traits in A) Sir Anthony Hopkins based on autobiographical descriptions in public interviews and B) Dr. Temple Grandin based on descriptions in her autobiographical books.

Another well-known person with autism, Dr. Temple Grandin, is well-established as a scientist in the cattle industry. Her success in revolutionizing that industry is bolstered by her analysis of the social and individual behavior of cows, as well as the environmental (social and architectural) influences around them. Dr. Grandin has described her work as involving all her senses, as a cow would. In this way, she observes how shadows, the movement of objects in the environment (such as chains on fences), and the shape of architecture affect the behavior of cows. She is also known for developing a squeeze device that provides her with comforting, physical pressure. This device shows her high levels of systemizing with object orientation and sensory exploration. Her academic accomplishments also show high memory and attention. She succeeded in a male-dominated field (antagonistic to women entering the field at the time), and her autobiographical accounts of childhood [40] demonstrate her high non-conformity (Fig. 4).

While both Dr. Grandin and Sir Hopkins seem to analyze the social world, their analysis may treat social dynamics in a manner similar to how other scientists treat non-social patterns in fields such as astronomy or geology. In the cases described here, Dr. Grandin views cows and Sir Hopkins views people as important objects of interest.

THE BAPCO-DISABILITY MATRIX PARADIGM

BAPCO and co-occurring conditions

Dr. Grandin and Sir Hopkins both received a diagnosis of autism, and they both have described experiencing challenging differences in development. Sir Hopkins had grave difficulty in school subjects and dropped out of school at 17 years old. Dr. Grandin describes not learning to speak before 3 years old, along with lifelong sensory sensitivities (sound, touch, odor) and a desire for aloneness. Grandin describes that the “‘people world’ was often too stimulating for my senses” [40].

Sir Hopkins and Dr. Grandin may have experienced BAPCO combined with other co-occurring conditions, such as dyslexia, hypersensitivities, or other underlying conditions. Autism often co-occurs with a broad range of medical conditions [41], including neurodevelopmental disorders [42], genetic conditions [43], psychiatric conditions [44], motor disorders [45], and physical and health disorders [46]. However, none of the associated conditions share a 100% concordance rate with autism.

I propose that the BAPCO can interact with other developmental disabilities in a model I call the BAPCO-Disability Matrix Paradigm (BAPCO-DMAP). This paradigm involves a 2 X 2 matrix of personality by disability (Fig. 5). In this matrix, an individual without a BAPCO who has a neurodevelopmental disability will be characterized as having the neurodevelopmental disability (eg, Fragile X syndrome). However, an individual with a BAPCO and a co-occurring disability will be characterized as having autism, despite whether their co-occurring condition is explicitly diagnosed. For example, not all individuals with autism have challenges with information processing, and such challenges are not explicitly intrinsic to autism. Yet, clinicians and educators may misclassify challenges in information processes as part of the individual’s spectrum of autistic traits.

Fig. 5.

The Broader Autism Phenotype Constellation-Disability Matrix Paradigm. This 2 X 2 matrix shows the degree of BAPCO traits (low, high) by impairment category (with or without a co-occurring disability). Individuals with high BAPCO traits and a co-occurring disability are categorized as “autism” or under autism and the identified co-occurring disability, such as “autism and Fragile X syndrome.” Individuals with low BAPCO traits and a co-occurring disability are categorized by the name of the identified disability alone, such as Fragile X syndrome or information processing disorder.

The individual’s age of diagnosis would likely vary based on the type of neurodevelopmental disability and the specific BAPCO traits. The greater the impact of the co-occurring condition at an early age, the more likely individuals would receive a diagnosis at an earlier age. The same would be true for individuals with specific BAPCO traits that can hinder early social learning. For example, individuals with an intellectual disability and BAPCO would likely be diagnosed earlier. Similarly, those with a neurodevelopment disability who have a strong object orientation and near absent social orientation would be diagnosed earlier. Thus, age should be an important consideration in the BAPCO model.

BAPCO and quality of life

Both disability and BAPCO traits fall along respective spectrums. Thus, the line between “higher functioning” autism (BAPCO with a co-occurring mild disability) and BAPCO (traits that may not always be socially welcomed) may be fuzzy. Nevertheless, both groups may need support to improve social skills and relationships that can enhance quality of life. For example, they may benefit from leadership and advocacy training, as well as receiving counseling to better navigate their relationships with family, friends, partners, co-workers, and authority figures. These trainings and counseling should be tailored to support the types of learning preferred within an individual’s constellation (eg, visual, verbal, lexical, systemizing).

BAPCO-DMAP and neurodiversity

To test the BAPCO-DMAP theory, culturally unbiased assessments that measure BAPCO traits would need to be developed and validated. Nevertheless, this paradigm could be used to test several predictions.

1. Based on the high heritability of autism and the involvement of common polygenetic variants, multiplex families with autism should have a higher representation of BAPCO constellations than families without autism.

2. BAPCO and autism will have lower prevalence in societies that do not have environmental contexts for individuals with these constellations to engage in assortative mating. Environments that prevent individuals (or matchmakers) from selecting mates on similar BAPCO traits will have lower rates of autism.

3. Based on the described educational/employment opportunity theory, traditional or orthodox societies that do not value innovation, non-conformity, or meritorious education practices may have a low prevalence of autism without co-occurring intellectual disability.

4. Individuals from higher socio-economic groups in the United States tend to have greater access to pursue educational and occupational opportunities based on personal preferences. Based on the BAPCO paradigm, an increased prevalence of BAPCO is likely to occur in higher socio-economic groups as an artifact of social capital.

5. Societies that value innovation, non-conformity, or meritorious education practices for men, but not women, will have an intermediate prevalence of BAPCO constellations. The less a society values women, or subgroups of women, who express traits associated with the BAPCO, the lower and more stable the prevalence of the BAPCO will be in that population/subgroup.

6. Based on access and educational/employment opportunities, BAPCO (and autism characteristics) would be represented at much lower rates in cultures that provide fewer educational and occupational opportunities for women.

7. Societies that value and provide opportunities for innovation, non-conformity, or meritorious education practices for both men and women will have the highest prevalence and rate of prevalence increases of BAPCO constellations.

8. Specific BAPCO traits in parents (eg, increased memory and attention, object orientation, non-conformity) may be associated with specific profiles of development or developmental timing.

CONCLUSIONS AND FUTURE DIRECTIONS

I propose that the BAPCO is an important expansion of the BAP that includes a constellation of socially valued traits. The frequency of these traits has increased due to assortative mating opportunities that occurred alongside social changes in education and occupational opportunities. This assortative mating can lead to both beneficial and detrimental (or, at least, challenging) developmental consequences that can affect social and language development. Also, the BAPCO-DMAP posits that the intersection of BAPCO traits and co-occurring conditions contributes to autism.

A major implication of the BAPCO-DMAP is the position of research on the cause, cure, or prevention of autism. The BAPCO-DMAP proposes that autism is either a) an extreme expression of normally distributed traits associated with the BAPCO, or b) consists of BAPCO traits coupled with a co-occurring disability. Thus, focusing on the cure or prevention of BAPCO-specific traits or the corresponding diagnosis of autism (disability with BAPCO traits) would be counterproductive. However, research focused on identifying the cause(s) and mitigating the detrimental effects of co-occurring disabilities and other conditions would continue to be beneficial.

Identifying specific constellations of BAPCO traits can inform interventions and child development practices. For example, children with increased attention and memory may need different language intervention techniques than children with object orientation and motor delays. But similar to individuals with autism, many individuals with BAPCO traits would likely benefit from support that helps them navigate the social world. The positive traits associated with either autism or the BAPCO have not been well studied. And only some studies have assessed systemizing traits. By expanding studies in this area, research and programs could focus on better tailoring education and intervention opportunities to meet the learning and motivation needs of individuals within the BAPCO and autism spectrums. These efforts would be beneficial to these individuals and to society.

Future research is also needed to identify and control for confounds of socioeconomics, social and institutional capital, cultural differences in trait acceptability, awareness, and stigma. However, given that common gene variances predict autism, a BAPCO measure could be used quantitatively with advances in genetic research.

Importantly, our understanding of the genetics of autism and the BAPCO are impacted by our definitions of the nature of these two constellations. Thus, we need to create a more comprehensive definition of autism that includes constellations of BAPCO traits. Further, the BAPCO-DMAP could be the model that paves the way to testable predictions and a better understanding of autism and its co-occurring conditions.