Start Here: A Simple Overview

The Shared Rhythms Framework asks a developmental question:

What happens when young children’s nervous systems are still built for deep, repeated, relational experience — but modern childhood gives many families less rhythm, less movement, less outdoor time, less shared doing, and less co-regulation than children’s developing systems may expect?

This page introduces the theory behind that question.

THE CORE IDEA

Children develop through the ongoing interaction between their nervous systems and the daily environments around them. The core idea is not that modern life causes autism; autism-related traits are biologically rooted, highly variable, and influenced by many factors. At the same time, early development does not unfold from biology alone. It unfolds through repeated experiences, relationships, routines, and environments that shape how a child’s nervous system organizes over time.

The theory, which I am calling “The Trait Visibility Amplification Model”, or TVAM, explores whether rapid changes in early childhood daily routines and activities may affect how underlying developmental vulnerabilities show up in everyday life.

IN SIMPLER TERMS

Some children may come into this world with nervous systems that need more rhythm, movement, co-regulation, sensory experience, repetition, and support to organize well. When modern family life makes those experiences harder to access consistently, those children may struggle more visibly with regulation, attention, communication, flexibility, sensory processing, and social engagement.

TVAM asks whether changed developmental conditions may amplify the visibility, intensity, clustering, or functional impact of autism-related traits for some children — especially during the earliest years, when the brain and body are highly responsive to repeated experience.

This is a research-informed framework, not a settled conclusion. It is meant to organize existing ideas from developmental science, clinical observation, early intervention, anthropology, ecology, and systems theory into a set of questions that can - and should - be studied more carefully.

This is not saying modern life causes autism, ADHD, or neurodivergence. It is asking what happens when children who already need more developmental support grow up in a world where movement, rhythm, co-regulation, connection, and shared routines are harder to access consistently.

A GUIDE TO THIS PAGE

The rest of this page walks through the ideas behind TVAM step by step.

First, it explains the foundational concepts the model is built on: experience-expectant development, sensitive periods, developmental ecology, trait visibility, and complex systems.

Then, it describes the clinical and cultural patterns that led to this question, including changes in daily rhythm, movement, outdoor time, caregiver capacity, co-regulation, and children’s participation in ordinary routines.

Finally, it outlines what TVAM proposes and why this framework may matter for early intervention, research, and the broader public policies that shape support for families.

The goal is not to blame parents, providers, screens, or modern life. The goal is to better understand the current developmental conditions children are growing inside — and to ask how early intervention, public policy, community systems, and family support can help restore the kinds of repeated, relational, body-based experiences young children need to participate, communicate, regulate, and connect.

Five Foundational Concepts

Established concepts informing the Trait Visibility Amplification Model.

  • Early development is not simply a matter of genetic unfolding. Children’s brains and bodies are shaped through repeated experience, especially during periods when neural systems are highly plastic and responsive to environmental input.

    Developmental science has long distinguished between experiences that are individually learned (“experience-dependent” development) and experiences the brain is biologically prepared to expect (“experience-expectant development”).

    In early childhood, repeated patterns of movement, social interaction, sensory input, communication, and caregiving help organize developing systems for regulation, attention, connection, and participation.

    Core idea: repeated experience becomes developmental structure.

    References: Greenough, Black, & Wallace, 1987; Knudsen, 2004

  • Young children do not receive developmental input in abstract categories. They receive it through the ordinary structure of daily life: being carried, fed, comforted, spoken to, moved, invited into routines, brought outdoors, included in family tasks, and supported through transitions.

    This means daily routines are not just schedules. They are the repeated pathways through which children encounter movement, language, sensory experience, emotional co-regulation, problem-solving, imitation, and belonging.

    When daily routines change, the pattern of developmental input changes too.

    Core idea: routines are how experience reaches the developing child.

    References: Spagnola, M., & Fiese, B. H. (2007). Family routines and rituals: A context for development in the lives of young children.

  • Human development was shaped across thousands of generations in environments where young children were embedded in close relationships, physical movement, outdoor life, mixed-age interaction, shared caregiving, and meaningful participation in daily tasks.

    This does not mean the past was ideal or that modern families should recreate it. It means children’s developing nervous systems were shaped around certain recurring patterns of experience. When those patterns become less available, less consistent, or more thinly spread, development may unfold under different conditions than the ones human neurodevelopment was built around.

    Core idea: modern children are born with ancient developmental expectations.

    References: Greenough, Black, & Wallace, 1987; Knudsen, 2004; Hewlett & Lamb, 2005; Hrdy, 2009; Konner, 2010.

  • In the context of human history, the daily lives of infants and toddlers have changed very quickly.

    Homo sapiens have existed for roughly 300,000 years. Agriculture began only around 12,000 years ago, and even that major transition unfolded across many generations. By comparison, the pace of change across the last 300 years — and especially the last 30 — is striking.

    Today, many families are raising young children inside conditions that are historically unusual: long work hours, childcare constraints, financial stress, reduced outdoor freedom, screen-saturated environments, smaller support networks, and more fragmented daily rhythms.

    These changes are not simply individual parenting choices. They reflect larger cultural, economic, technological, and social shifts that shape what families can realistically provide.

    From a developmental systems perspective, this matters because children do not develop in isolation. They develop within nested environments: family routines, caregiver stress, childcare systems, community supports, cultural expectations, and historical time all interact to shape early development.

    Bronfenbrenner’s ecological theory is especially useful here because it frames development as occurring within interconnected systems surrounding the child, rather than inside the child alone.

    Core idea: modern childhood has changed at the level of daily developmental input.

    References: Smithsonian National Museum of Natural History; Bronfenbrenner, 1979; National Academies, 2015; Diamond, 2012.

  • Autism-related traits are not all-or-nothing traits that appear only in children with a diagnosis. Research suggests that these traits exist in varying degrees across the general population and are influenced by underlying genetic and neurodevelopmental factors.

    The Trait Visibility Amplification Model builds from this understanding. It asks whether rapidly changed patterns of early experience may interact with underlying neurodevelopmental vulnerability to shape when, how intensely, and how functionally visible autism-related traits become.

    In this view, modern conditions do not “create” autism in a simple, direct way. Instead, they may influence how underlying developmental vulnerabilities are expressed, supported, intensified, buffered, or made more visible within everyday life.

    This distinction matters. A child’s developmental profile does not emerge from biology alone, and it does not emerge from environment alone. It emerges through the ongoing interaction between the child’s nervous system and the conditions surrounding development.

    Core idea: traits emerge within contexts — and context can shape visibility, intensity, and functional impact.

    References: Constantino, J. N., & Todd, R. D. (2003). Autistic traits in the general population: A twin study. Archives of General Psychiatry, 60(5), 524–530.
    Constantino, J. N., & Todd, R. D. (2005). Intergenerational transmission of subthreshold autistic traits in the general population. Biological Psychiatry, 57(6), 655–660.
    Robinson, E. B., et al. (2016). Genetic risk for autism spectrum disorders and neuropsychiatric variation in the general population. Nature Genetics, 48, 552–555.
    Lord, C., et al. (2020). Autism spectrum disorder. Nature Reviews Disease Primers, 6, 5.
    Belsky, J., & Pluess, M. (2009). Beyond diathesis stress: Differential susceptibility to environmental influences. Psychological Bulletin, 135(6), 885–908.

A Deeper Look at the Developing Framework

The five foundational ideas above offer a brief introduction to TVAM. The sections below expand the framework in greater depth, drawing from clinical observation, developmental theory, evolutionary mismatch, experience-expectant development, complex systems thinking, and preliminary research questions.

This work is still in progress. TVAM is not presented as a settled conclusion, but as a research-informed framework intended to organize existing evidence, generate testable hypotheses, and invite interdisciplinary study.

The sections below are intentionally brief. They are meant to introduce the framework, not serve as a complete academic paper. Longer essays and a working paper will expand each area over time.

  • This framework began with repeated patterns of clinical observation.

    Across my work with infants, toddlers, and families, one pattern has become increasingly difficult to ignore: many of the ordinary experiences that support early development — movement, co-regulation, sensory exploration, shared interaction, outdoor time, and participation in daily routines — appear to be less frequent, less sustained, and more fragmented across modern early childhood than our developmental models often account for. In other words, the concern is not simply that children’s environments have changed, but that the density of experience-expectant inputs may be thinner across daily life at scale.

    Alongside this, I have become increasingly interested in the complex and uneven developmental profiles many young children present with across regulation, attention, sensory processing, communication, motor planning, flexibility, and social engagement. These variable profiles are not surprising from a complex systems perspective: development emerges through many interacting systems organizing together over time. If early development depends on repeated patterns of experience, then changes in the density, timing, and consistency of those experiences may help explain why developmental pathways appear increasingly variable — especially for children with biologically rooted vulnerabilities.

    These observations are not presented as proof. My own clinical eye has changed over time, and I may notice patterns now that I would not have recognized earlier in my career. For that reason, these observations are best understood as the starting point for inquiry, not as settled evidence.

    These observations raise broader questions about child development and developmental change. Autism identification has increased substantially, with recent CDC surveillance estimating ASD identification among 8-year-old children at 1 in 31 in 2022. Families also face long waits for developmental and autism evaluations in many areas. Whether rising identification reflects true prevalence, broader criteria, improved awareness, increased service-seeking, or some combination of these forces, the growing demand for help points to a real functional concern in children, families, schools, and clinical systems.

    Existing explanations remain important. Increased awareness, broader diagnostic criteria, improved screening, genetic liability, and prenatal influences all help explain changes in who is identified and when. But they do not fully answer a postnatal developmental question:

    How might early developmental environments shape the timing, variability, and functional impact of autism-related traits after birth?

    TVAM begins with this missing question. It asks what may happen when biologically conservative, experience-expectant developmental systems encounter rapid ecological change during sensitive periods of early development.

    The goal is not to argue that modern life “causes” autism. Instead, TVAM offers a framework for examining how rapid changes in early developmental ecology may interact with underlying neurodevelopmental vulnerability — influencing when traits become visible, how strongly they affect functioning, and whether some children cross clinical or diagnostic thresholds earlier.

    Core idea: repeated patterns of clinical observation can generate important research questions — especially when child development and daily ecology appear to be shifting at scale — but those questions must be tested carefully.

    Selected References: CDC, 2025; Lord et al., 2020; Constantino & Todd, 2003; Greenough, Black, & Wallace, 1987; Knudsen, 2004.

  • Early development is not simply a process of genetic unfolding. Young children’s brains and bodies are biologically prepared to build themselves through experience — especially during early periods of heightened plasticity, when neural systems are especially responsive to input from the surrounding environment.

    Developmental science has long distinguished between experiences that are individually learned and experiences the developing brain is prepared to expect. These expected experiences are not luxuries or enrichment. They are part of the ordinary developmental conditions through which young nervous systems organize.

    In early childhood, repeated patterns of movement, touch, social interaction, sensory experience, communication, emotional co-regulation, and participation in daily routines help shape systems involved in attention, regulation, learning, connection, and adaptive functioning.

    This matters for TVAM because if young children’s developmental systems are built through repeated patterns of experience, then large-scale changes in those patterns may alter the conditions under which development unfolds.

    Core idea: repeated experience becomes developmental structure.

    Selected References: Greenough, Black, & Wallace, 1987; Knudsen, 2004; Shonkoff & Phillips, 2000; National Scientific Council on the Developing Child, 2007.

  • Human babies are not born as blank slates. They are born with developing nervous systems that have been shaped across deep evolutionary time to expect certain recurring patterns of care, movement, sensory experience, social connection, and participation in daily life.

    For most of human history, early development unfolded in close proximity to caregivers and other children, with frequent physical contact, outdoor exposure, shared caregiving, mixed-age interaction, imitation, movement, and participation in the ordinary tasks of the group.

    This does not mean the past was ideal, safe, or something modern families should recreate. It means that human neurodevelopment was shaped around certain repeated patterns of experience. When those patterns become less available, less consistent, or more thinly spread across daily life, children may be developing under conditions that differ from the ones their brains and bodies were built to expect.

    A central clinical observation behind TVAM is that these experience-expectant inputs have not simply changed in kind; in many modern childhoods, they may also be less dense across the day. Movement, outdoor time, sensory exploration, shared doing, co-regulation, face-to-face interaction, and participation in real-life routines may still occur, but they are often less frequent, less sustained, less varied, or more interrupted than the developmental systems receiving them were shaped to expect.

    In practice, this may look like children spending less time moving freely through space, fewer moments of shared adult-child attention during ordinary routines, more time being entertained rather than participating, fewer opportunities to imitate real tasks, less outdoor sensory variation, or fewer sustained periods of co-regulation with an available adult. These changes are often not the result of individual parenting choices alone, but of the broader conditions modern families are living within.

    This matters for TVAM because biologically conservative developmental systems may not adjust quickly to rapid cultural change. Modern children may live in a radically altered world, but they are still born with ancient developmental expectations.

    From a clinical perspective, this shifts the question from “What skill is missing?” to “What patterns of daily experience is this child’s developing system actually receiving — and are the expected inputs frequent, sustained, varied, and relational enough to support the systems being asked to develop?”

    Core idea: modern children are born with ancient developmental expectations, but many of the everyday experiences those systems expect may no longer be occurring with the frequency, rhythm, and density needed across early childhood at scale.

    Selected References: Greenough, Black, & Wallace, 1987; Knudsen, 2004; Hewlett & Lamb, 2005; Hrdy, 2009; Konner, 2010.

  • In the context of human history, the daily lives of infants and toddlers have changed very quickly.

    Homo sapiens have existed for roughly 300,000 years. Agriculture began only around 10,000–12,000 years ago, and even that major transition unfolded unevenly across regions and across many generations. By comparison, the pace of change across the last 300 years — and especially the last 30 — is striking.

    Today, many families are raising young children inside conditions that are historically unusual:

    • less shared caregiving

    • less mixed-age community life

    • fewer natural opportunities for outdoor movement

    • more time indoors, more time with screens

    • fewer chances for young children to be embedded in the ordinary work of daily life.

    Many children have fewer opportunities to walk, climb, pull, carry, sort, wash, help, imitate, problem-solve, and participate in meaningful routines.

    At the same time, many parents are raising children with less support, less community presence, and fewer natural opportunities for co-regulation across the day.

    These changes are not simply individual parenting choices. They reflect larger cultural, economic, technological, and social shifts that shape what families can realistically provide.

    From a developmental systems perspective, this matters because children do not develop in isolation. They develop within nested environments: family routines, caregiver stress, childcare systems, community supports, cultural expectations, and historical time all interact to shape early development. Bronfenbrenner’s ecological theory is especially useful here because it frames development as occurring within interconnected systems surrounding the child, rather than inside the child alone.

    TVAM asks whether the speed and scale of modern cultural change may be developmentally important, especially when those changes affect the repeated daily experiences through which young children organize regulation, attention, movement, communication, flexibility, and connection.

    Core idea: modern childhood has changed rapidly at the level of daily developmental input.

    Selected references:
    Smithsonian National Museum of Natural History. Our species arose at least 300,000 years ago.
    Encyclopaedia Britannica. Origins of agriculture.
    Bronfenbrenner, U. (1979). The Ecology of Human Development: Experiments by Nature and Design. Harvard University Press.
    Diamond, J. (2012). The World Until Yesterday: What Can We Learn from Traditional Societies? Viking.

  • Not all children respond to developmental conditions in the same way.

    Some children may remain relatively regulated and adaptive across a wide range of environments. Others may be more sensitive to changes in rhythm, movement, sensory input, social predictability, co-regulation, caregiver stress, or participation in daily life.

    This variability matters. If children differ in underlying neurodevelopmental vulnerability, then the same environmental shift may not have the same developmental effect for every child. A change that is manageable for one child may be more destabilizing for another, especially during sensitive periods of early development.

    TVAM is especially interested in this interaction: how rapidly changed patterns of daily experience may affect children differently depending on their underlying developmental profile, biological sensitivity, and available supports.

    This helps explain why the framework is not a simple “modern life causes developmental differences” argument. It is an interactional model. It asks how changed developmental conditions may amplify, buffer, or reveal vulnerabilities differently across children.

    Core idea: changed conditions do not affect all children equally; vulnerability and context interact.

    Selected references:
    Belsky & Pluess, 2009; Ellis et al., 2011; Pluess, 2015; Boyce, 2019.

  • The Trait Visibility Amplification Model proposes that rapid cultural change has altered the daily routines and activities through which young children develop, changing patterns of developmental input at scale.

    The model begins with two premises. First, autism-related traits are not all-or-nothing traits that appear only in children with a diagnosis. Traits associated with the broader autism phenotype exist in varying degrees across the population and reflect underlying neurodevelopmental variation. Second, young children’s developing systems are experience-expectant: they organize through repeated patterns of movement, sensory experience, co-regulation, communication, social interaction, and participation in daily life.

    TVAM asks what may happen when children with underlying autism-related trait vulnerability develop within environments that provide less of the regulatory, social, sensory, motor, and participatory support their nervous systems may need.

    The central hypothesis is that rapidly changed developmental conditions may amplify the visibility, intensity, clustering, and functional impact of autism-related traits for some children. In other words, changed patterns of early experience may not create traits from nothing, but may influence how traits organize, when they become noticeable, how strongly they affect functioning, and whether a child crosses clinical or diagnostic thresholds.

    This is what I mean by trait visibility amplification: the possibility that altered developmental input can make underlying traits more functionally visible within everyday life.

    TVAM does not suggest that modern life simply “causes” autism. Rather, it proposes an interaction: children with autism-related trait vulnerability may be especially sensitive to the specific ways childhood has changed — including reduced movement, less shared caregiving, more fragmented adult attention, fewer natural opportunities for co-regulation, and less participation in the ordinary work of daily life.

    In earlier human ecologies, some traits may have been buffered by dense social support, predictable rhythms, repeated movement, shared caregiving, outdoor life, and meaningful participation. Modern childhood may provide these buffering experiences less consistently and less reliably. TVAM asks whether this thinning of experience-expectant developmental support may amplify the visibility and functional impact of autism-related traits for some children.

    Core idea: TVAM proposes that rapid cultural change may interact with autism-related trait vulnerability, shaping when, how strongly, and how functionally visible those traits become.

    Selected references: Constantino & Todd, 2003; Constantino & Todd, 2005; Robinson et al., 2016; Lord et al., 2020; Belsky & Pluess, 2009; CDC, 2025.

  • If young children develop through repeated patterns of daily experience, then early intervention cannot focus only on isolated skills. It must also consider the broader ecology surrounding the child.

    This means asking not only, “What can this child do?” but also: What patterns of experience is this child receiving every day? How often does the child move through space, go outside, use their hands, participate in real routines, communicate within shared activities, receive co-regulation, and experience predictable rhythms of connection?

    From this perspective, intervention is not just about teaching a child a discrete skill. It is about helping restore some of the experience-expectant patterns that young nervous systems were shaped to develop through: movement, outdoor life, shared attention, co-regulation, sensory-rich play, communication within real routines, meaningful participation, and predictable daily rhythm.

    This is not a call to place more burden on parents. Many families are already stretched by work demands, childcare limitations, financial pressure, isolation, and lack of community support. Early intervention must therefore support the broader caregiving ecology — helping families identify what is missing, what is already working, and what can be made more available within the realities of daily life.

    TVAM points toward an early intervention model that looks beyond the therapy session and asks how families, clinicians, childcare providers, communities, and systems can help rebuild the daily conditions that support regulation, attention, movement, communication, flexibility, connection, and participation.

    Core idea: early intervention should support the ecology of daily life so children have more access to the repeated experiences through which development happens.

    Selected references: Shonkoff & Phillips, 2000; Dunst et al., 2001; Spagnola & Fiese, 2007; National Scientific Council on the Developing Child, 2007.

  • TVAM is intended to be a hypothesis-generating framework, not a final conclusion.

    If early development is shaped through repeated patterns of experience, and if those patterns have changed rapidly at scale, then researchers can begin asking more specific questions about how modern developmental ecology may relate to early outcomes.

    This includes questions about movement, outdoor time, screen exposure, caregiver stress, co-regulation, social rhythm, mixed-age interaction, sensory experience, participation in daily routines, and the availability of community support. These variables are often studied separately, but TVAM suggests they may need to be examined together as part of a broader developmental ecology.

    The framework also invites more careful study of developmental variability. Which children appear most sensitive to changed conditions? Which supports buffer vulnerability? Which patterns of daily experience are most strongly associated with regulation, attention, communication, flexibility, movement, sensory processing, and social engagement?

    TVAM proposes that researchers may be underestimating how substantially the density of ordinary experience-expectant inputs has changed. The question is not only whether children still have access to movement, interaction, outdoor play, sensory exploration, and co-regulation, but whether these inputs occur with enough frequency, duration, variety, and relational continuity to support the developmental systems that depend on them.

    TVAM does not replace genetic, prenatal, diagnostic, or neurobiological models of autism. Instead, it adds a postnatal ecological question: how might rapidly changed early environments influence the expression, clustering, timing, and functional impact of underlying autism-related traits?

    Ultimately, the purpose of this research is not simply to explain developmental change, but to identify supports that improve children’s participation in daily life and reduce stress on children, caregivers, and family systems.

    Core idea: TVAM offers a framework for generating testable questions about developmental input, trait vulnerability, and early outcomes.

    Selected references: Bronfenbrenner, 1979; Greenough, Black, & Wallace, 1987; Knudsen, 2004; Belsky & Pluess, 2009; Ellis et al., 2011; Lord et al., 2020.

  • If TVAM is even partially correct, then early development cannot be understood only as a matter of individual parenting choices, clinical services, or child-level traits. It must also be understood as a public, cultural, and policy issue.

    If young children’s nervous systems are shaped through repeated patterns of daily experience, then society has to ask whether modern family life still makes those experiences realistically available. Families cannot provide movement-rich, relationship-rich, outdoor, predictable, socially supported childhoods through individual effort alone if the surrounding systems make those rhythms difficult to sustain.

    This has implications for how we think about childcare, parental leave, work schedules, safe outdoor spaces, community support, pediatric guidance, early intervention access, screen-saturated environments, and public education for families.

    The goal is not to blame parents or romanticize the past. The goal is to ask what kinds of supports would help restore the daily patterns of movement, co-regulation, communication, participation, sensory experience, and belonging that young children’s nervous systems were shaped to expect.

    If early developmental input is shaped by the conditions surrounding families, then supporting children means supporting the ecology around them.

    Core idea: if daily developmental input is socially shaped, then early development is also a public policy issue.

    Selected references: Bronfenbrenner, 1979; Shonkoff & Phillips, 2000; National Scientific Council on the Developing Child, 2007; Diamond, 2012.

  • TVAM is a developing theoretical framework, not a settled conclusion.

    It does not claim that modern life simply “causes” autism. It does not reduce autism to parenting, screens, childcare, or any single environmental factor. It also does not deny the importance of genetics, prenatal influences, neurobiology, diagnostic criteria, screening practices, or increased awareness.

    Instead, TVAM asks a narrower and more specific question: how might rapid changes in early developmental ecology interact with underlying neurodevelopmental vulnerability to shape the timing, intensity, clustering, and functional visibility of autism-related traits?

    This distinction matters. The goal is not to explain autism through environment alone, but to study the interaction between biology and context more carefully — especially during early developmental periods when regulation, attention, movement, communication, sensory processing, flexibility, and social engagement are rapidly organizing.

    TVAM should be understood as a framework for inquiry. It is meant to organize observations, generate testable hypotheses, invite interdisciplinary research, and help identify supports that improve participation in daily life for children and families.

    Core idea: TVAM is an interactional model, not a simple cause-and-effect claim.

    Selected references: Lord et al., 2020; Constantino & Todd, 2003; Greenough, Black, & Wallace, 1987; Knudsen, 2004; Belsky & Pluess, 2009.

  • Belsky, J., & Pluess, M. (2009). Beyond diathesis stress: Differential susceptibility to environmental influences. Psychological Bulletin, 135(6), 885–908. https://doi.org/10.1037/a0017376 (PubMed)

    Boyce, W. T. (2019). The Orchid and the Dandelion: Why Some Children Struggle and How All Can Thrive. Alfred A. Knopf.

    Bronfenbrenner, U. (1979). The Ecology of Human Development: Experiments by Nature and Design. Harvard University Press.

    Centers for Disease Control and Prevention. (2025). Prevalence and early identification of autism spectrum disorder among children aged 4 and 8 years — Autism and Developmental Disabilities Monitoring Network, 16 sites, United States, 2022. MMWR Surveillance Summaries, 74(2), 1–22. (CDC)

    Constantino, J. N., & Todd, R. D. (2003). Autistic traits in the general population: A twin study. Archives of General Psychiatry, 60(5), 524–530. https://doi.org/10.1001/archpsyc.60.5.524 (PubMed)

    Constantino, J. N., & Todd, R. D. (2005). Intergenerational transmission of subthreshold autistic traits in the general population. Biological Psychiatry, 57(6), 655–660. https://doi.org/10.1016/j.biopsych.2004.12.014 (PubMed)

    Diamond, J. (2012). The World Until Yesterday: What Can We Learn from Traditional Societies? Viking.

    Dunst, C. J., Bruder, M. B., Trivette, C. M., Hamby, D., Raab, M., & McLean, M. (2001). Characteristics and consequences of everyday natural learning opportunities. Topics in Early Childhood Special Education, 21(2), 68–92. (Sage Journals)

    Ellis, B. J., Boyce, W. T., Belsky, J., Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2011). Differential susceptibility to the environment: An evolutionary-neurodevelopmental theory. Development and Psychopathology, 23(1), 7–28.

    Encyclopaedia Britannica. (n.d.). Origins of agriculture.

    Greenough, W. T., Black, J. E., & Wallace, C. S. (1987). Experience and brain development. Child Development, 58(3), 539–559.

    Hewlett, B. S., & Lamb, M. E. (Eds.). (2005). Hunter-Gatherer Childhoods: Evolutionary, Developmental, and Cultural Perspectives. Aldine Transaction.

    Hrdy, S. B. (2009). Mothers and Others: The Evolutionary Origins of Mutual Understanding. Harvard University Press.

    Knudsen, E. I. (2004). Sensitive periods in the development of the brain and behavior. Journal of Cognitive Neuroscience, 16(8), 1412–1425.

    Konner, M. (2010). The Evolution of Childhood: Relationships, Emotion, Mind. Belknap Press of Harvard University Press.

    Lord, C., Brugha, T. S., Charman, T., Cusack, J., Dumas, G., Frazier, T., Jones, E. J. H., Jones, R. M., Pickles, A., State, M. W., Taylor, J. L., & Veenstra-VanderWeele, J. (2020). Autism spectrum disorder. Nature Reviews Disease Primers, 6, Article 5. https://doi.org/10.1038/s41572-019-0138-4 (Nature)

    National Scientific Council on the Developing Child. (2007). The timing and quality of early experiences combine to shape brain architecture: Working Paper No. 5. Center on the Developing Child at Harvard University.

    Pluess, M. (2015). Individual differences in environmental sensitivity. Child Development Perspectives, 9(3), 138–143.

    Robinson, E. B., St Pourcain, B., Anttila, V., Kosmicki, J. A., Bulik-Sullivan, B., Grove, J., Maller, J., Samocha, K. E., Sanders, S. J., Ripke, S., Martin, J., Hollegaard, M. V., Werge, T., Hougaard, D. M., Neale, B. M., Evans, D. M., Skuse, D., Mortensen, P. B., Børglum, A. D., Ronald, A., … Daly, M. J. (2016). Genetic risk for autism spectrum disorders and neuropsychiatric variation in the general population. Nature Genetics, 48(5), 552–555. https://doi.org/10.1038/ng.3529 (PubMed)

    Shonkoff, J. P., & Phillips, D. A. (Eds.). (2000). From Neurons to Neighborhoods: The Science of Early Childhood Development. National Academy Press.

    Smithsonian National Museum of Natural History. (n.d.). Our species arose at least 300,000 years ago.

    Spagnola, M., & Fiese, B. H. (2007). Family routines and rituals: A context for development in the lives of young children. Infants & Young Children, 20(4), 284–299. (Illinois Experts)

A Developing Framework

TVAM is a developing conceptual framework, not a settled conclusion.

It is intended to organize clinical observations, generate testable research questions, and support a more compassionate public conversation about early development, autism-related traits, and modern childhood.

The full academic version of this framework is being developed in an ongoing working paper. This website offers a more accessible introduction to the core ideas and their implications for clinicians, families, researchers, and policy makers.

At its heart, TVAM is an attempt to move beyond blame and beyond false choices.

Autism-related traits are real. Biology matters. Environment matters. Timing matters. Support matters.

And if the developmental mismatch is happening earlier, then our support must begin earlier too — not only through therapy and diagnosis but through the daily rhythms, relationships, environments, and policies that shape early life.

Real World Implications

If TVAM is even partially correct, the implications extend beyond autism research. The framework would invite us to rethink how we support early development across clinical practice, family education, childcare, public policy, and the built environment.

Two young girls in dresses planting a garden in a raised bed, one using a small gardening tool, near a sign that reads 'Kids Veggie Patch'.

Clinical Practice

Clinical work would need to look beyond isolated skills and behaviors to the broader developmental ecology surrounding the child. Assessment and intervention would ask not only what a child can or cannot do, but what repeated patterns of movement, co-regulation, communication, sensory experience, participation, and daily rhythm are available across the child’s everyday life.

Parent and Caregiver Education

Parent education would shift away from simply giving families more strategies to perform. Instead, it would help caregivers understand the kinds of daily experiences young children’s nervous systems are shaped to expect — and how to restore some of those patterns realistically within modern family life.

Early Intervention and Childcare

Early intervention and childcare systems would place greater emphasis on movement, outdoor time, predictable rhythm, mixed-age interaction, meaningful participation, co-regulation, hands-on activity, and family support. The goal would not be to add more pressure to adults, but to make developmentally supportive patterns easier to access and repeat.

Public Policy

Early development would be recognized as a public health and policy issue, not only a private parenting concern. Policies related to childcare access, parental leave, work schedules, family support, early intervention, community spaces, and screen-saturated environments would all become relevant to developmental outcomes.

Urban Design and Housing

The built environment would matter more. Housing, apartment complexes, neighborhoods, and public spaces would be evaluated partly by whether they make it easy for young children and families to access outdoor movement, safe play, social connection, mixed-age interaction, and everyday community life.

Research

Research would need to examine developmental inputs as patterns, not just isolated variables. Movement, screen exposure, caregiver stress, routines, social support, outdoor time, and family attention ecology may need to be studied together as part of a larger early developmental system.

How You Can Help

This work is still developing, and I do not believe it should develop in isolation.

Shared Rhythms began with clinical observation, but it will need many kinds of voices to become useful: early intervention providers, therapists, parents, researchers, pediatric clinicians, pediatricians, educators, policy makers, writers, and advocates.

If you are seeing similar patterns, asking similar questions, or working in a related area, I would love to hear from you.

If you know someone who may be interested in this work, please consider forwarding this website to them. I am especially interested in connecting with clinicians, researchers, early childhood professionals, educators, writers, journalists, and others exploring how modern childhood is shaping development.

The goal is not to rush toward certainty. The goal is to create a more serious, compassionate, and interdisciplinary conversation about how early development is changing — and what children and families need now.

Ways to contribute include:

  • sharing clinical or caregiving observations

  • helping identify relevant research

  • collaborating on research questions

  • connecting this work to early childhood policy

  • inviting conversation through podcasts, writing, presentations, or professional groups

  • helping make the framework more visible to clinicians, families, and researchers

Contact Mariam