Why does nature matter
for children?

The hypothesis that humans possess an evolved tendency to attend to and affiliate with life and living systems.

Edward O. Wilson was an American biologist and Harvard professor who popularized the modern concept of biophilia; Yale social ecologist Stephen Kellert helped develop it into the broader Biophilia Hypothesis.

Natural environments may support recovery from stress, including changes in emotional and physiological arousal.

Roger Ulrich is a researcher in environmental psychology and evidence-based healthcare design whose influential studies of responses to natural and built environments helped establish Stress Reduction Theory.

Nature may engage attention more gently—through “soft fascination”—allowing effortful directed attention opportunities to recover.

Rachel and Stephen Kaplan were environmental psychologists at the University of Michigan whose research on how people perceive and respond to environments led to Attention Restoration Theory.

Regulation, sensory experience, movement, relationships and patterned experiences can shape the conditions in which higher-order learning occurs. The Neurosequential Model is a developmental framework rather than direct evidence that nature itself produces these effects.

Bruce D. Perry is an American psychiatrist and neuroscientist whose clinical and research work with children affected by trauma and developmental adversity led him to develop the Neurosequential Model.

Movement and vestibular experiences have long influenced therapeutic and educational approaches, including Frank Belgau's work. Specific claims about the Belgau approach require careful interpretation because the independent evidence base is limited.

Frank Belgau was an educator who developed movement- and balance-based activities intended to support learning; his work became the basis of the Learning Breakthrough Program, although independent evidence for its specific claims remains limited.

Ultraviolet B (UVB) radiation from sunlight can trigger vitamin D synthesis in exposed skin. Vitamin D is important for calcium absorption and bone health, and deficiency can cause rickets in children. This is a sunlight pathway—not a benefit unique to nature: outdoor time in many settings can provide sunlight exposure. Sun exposure also carries skin-cancer risk, so vitamin D should not be used as a reason to encourage unprotected UV exposure; diet and supplementation are additional sources.

This is not a theory attributable to a single originator, but an established physiological pathway built from decades of research showing that ultraviolet B radiation can initiate vitamin D synthesis in human skin.

Contact with biodiverse environments may alter microbial exposure and immune regulation. A daycare biodiversity intervention found changes in children's microbiota and markers associated with immune regulation.

This pathway emerged from research across microbiology, immunology and evolutionary medicine, including the hygiene, old-friends and biodiversity hypotheses, rather than from a single originator.

Nature and horticulture can provide enabling environments in which young people build assets, exercise agency and make meaningful contributions.

Positive Youth Development emerged from developmental science and youth-development practice; developmental psychologist Richard M. Lerner and colleagues developed the influential Five Cs model of competence, confidence, connection, character and caring.

Natural settings can provide contexts for exploration, caregiver-child interaction, peer connection, belonging and place attachment. Evidence supports possible socioemotional benefits, but nature exposure should not be interpreted as directly producing secure attachment.

Modern attachment theory was founded by British psychiatrist John Bowlby and advanced empirically by developmental psychologist Mary Ainsworth, whose work examined how early caregiver relationships shape children's security and exploration.

Children develop through relationships and interactions within multiple environmental contexts over time. Health therefore exists not only within a child, but between children, families, communities and places.

Urie Bronfenbrenner was a developmental psychologist at Cornell University who developed ecological systems theory to explain how children's development unfolds through interactions with families, communities, institutions and the wider social environment.

Green space can influence environmental exposures including heat and noise, while vegetation and green infrastructure may also alter exposure to air pollution. Effects vary by setting, vegetation and design.

This is not a single-originator theory but a pathway synthesized across environmental health, epidemiology, urban ecology and public-health research examining how green environments can modify exposures such as heat, noise and air pollution.

Trees and plants release volatile compounds, including compounds often discussed as phytoncides, that are being investigated as possible biological pathways linking forest exposure and health. Much of this evidence is not pediatric, so this remains an emerging mechanism.

This is an emerging research area rather than a theory with one originator, drawing on forest medicine, plant chemistry and immunology to investigate whether volatile compounds released by plants may contribute to physiological responses to forest exposure.

Growing and caring for living things can create opportunities for responsibility, skill building, agency and contribution: I chose this. I learned this. I cared for this. I helped this grow.

This pathway draws especially on Positive Youth Development and related developmental theories; Richard M. Lerner and other developmental scientists have emphasized young people's strengths, agency and opportunities to contribute as features of healthy development.