The Science of Why

How Social, Behavioral, and Structural Factors Shape Health

BY MARIE RIENZO AND KARIN HAN, OBSSR

Human behavior shapes health in powerful ways. In NIH’s Intramural Research Program (IRP), investigators conducting behavioral and social sciences research (BSSR) dig into the “why” behind the “how” of health—how we think, feel, act, and interact, and how those patterns influence everything from disease risk to recovery.

Human behavior shapes health in powerful ways. In NIH’s Intramural Research Program (IRP), investigators conducting behavioral and social sciences research (BSSR) dig into the “why” behind the “how” of health—how we think, feel, act, and interact, and how those patterns influence everything from disease risk to recovery.

“Behavioral, social, and structural factors drive many of the leading causes of morbidity and mortality. They point the way to prevention and better health,” said Jane Simoni, NIH associate director for Behavioral and Social Sciences Research and director of the Office of Behavioral and Social Sciences Research (OBSSR). “IRP is advancing this work, showing why integrating behavioral and social sciences into biomedical research is essential to NIH’s mission.”

By uncovering the drivers of healthy habits like good sleep hygiene or of high-risk behaviors like inactivity, poor diet, and tobacco use, IRP scientists are developing smarter, more culturally responsive interventions. The goal is to reduce preventable disease, close health gaps, and turn data into real-world solutions that work for all communities.

At its heart, BSSR at NIH is about connecting discovery to everyday life, transforming science into strategies that help people live longer, healthier lives.

Science in the community

For Tiffany Powell-Wiley, senior investigator at NHLBI, tackling cardiovascular disease means looking beyond the clinic and into the neighborhoods where people live. Her lab studies how social determinants—such as access to healthy food, safe spaces for exercise, and exposure to chronic stress—interact with biology to shape obesity risk and heart health.

“Obesity is often the first stage toward developing not only heart disease, but also diabetes and even kidney and cerebrovascular diseases,” she explains. “Those at highest risk often have the [fewest] resources and the highest environmental stressors.”

To unravel these complex connections, Powell-Wiley’s team integrates data at multiple scales, from Global Positioning System mapping of where participants spend their time, to wearable devices tracking physical activity, to detailed immune cell measurements. Large epidemiologic datasets reveal patterns, whereas community-based studies test interventions that might work in real-world, under-resourced settings.

At the center of this work is the Hope Center in Northeast Washington, D.C., a research site embedded within a senior housing development. Born from years of relationship-building in local churches, libraries, and community spaces, the Hope Center allows residents to participate in studies, receive health screenings, and connect with educational programs without traveling to the NIH Clinical Center.

Powell-Wiley says this embedded approach is about more than convenience; it’s about trust. “It’s fragile. You can’t take it for granted,” she says. “It takes time, presence, and partnerships with trusted community leaders.”

The payoff? Interventions that aren’t just theoretically sound, but culturally relevant and sustainable. Whether testing digital tools to boost physical activity or measuring how perceptions of safety affect health behaviors, her lab aims for results that improve lives and empower communities.

“I don’t see this work as something that’s just for my lab,” she says. “I hope we’re a resource—a bridge between NIH and the communities we serve.”

Cracking the brain’s code

From making a morning cup of coffee to navigating a complex social interaction, our brains rely on a set of high-level cognitive processes known as executive functions. These “cognitive building blocks” allow us to focus our attention, resist impulsive urges, juggle information in working memory, and make decisions in the face of risks. But when these systems falter—as they often do in disorders such as schizophrenia, obsessive-compulsive disorder, depression, and post-traumatic stress disorder—daily life can become a maze without a map.

Executive dysfunction can make “folks unable to get on with their daily lives and activities,” says Yogita Chudasama, chief of the Section on Behavioral Neuroscience at NIMH and director of the Rodent Behavioral Core (RBC). “Even when treatments reduce symptoms, they often have little to no impact on executive functioning. These enduring cognitive deficits really impact people’s recovery and rehabilitation.”

Chudasama’s lab focuses on the brain networks that make executive function possible, particularly the prefrontal cortex and its partnerships with other cortical and subcortical regions. Her approach bridges human neuropsychology with animal research, using tasks that allow for cross-species comparisons, from humans to rats to monkeys. “Each animal has its own unique advantages,” she explains. For example, rats excel at spatial and odor-based tasks, whereas monkeys are better suited for visual and social-based tasks.

Recently, her team has expanded into studying how executive function intersects with socioemotional regulation, how we process feelings, interpret social cues, and build relationships. The link, she says, is stronger than it might appear. “The circuits involved in high-level cognitions are pretty much exactly the same circuits involved in socioemotional regulation.”

To explore these connections, her group observes marmosets, small monkeys that are well-suited for developmental studies. With their rich social lives, cooperative caregiving, and audible vocalizations, marmosets offer a unique window into how early-life experiences shape brain circuits, and, in turn, future cognition and emotional health.

In addition to leading her own research, Chudasama directs the NIMH RBC, a state-of-the-art facility supporting researchers at IRP. The RBC offers tools for assessing rodent behavior across cognitive, emotional, sensory, and motor domains, whether for mental health studies or conditions as far-ranging as cancer, diabetes, and infectious disease.

Two emerging trends are shaping the RBC’s future: Recording brain activity during natural social interactions and measuring behavior over long time periods in home-cage environments. Both promise more realistic, reproducible insights into how brains work in the real world.

Looking ahead, Chudasama’s priority is to understand how brain development—from before birth through adulthood—sets the stage for lifelong cognitive and emotional health. “By the time a child expresses severe distress, it may already be too late to intervene effectively,” she said. “We need to understand the earliest changes in brain development to make a real difference.”

Her message to colleagues across NIH is clear: Behavior is essential to understanding disease models, a window into the brain’s core functions. “It’s the readout of everything the nervous system and body are doing,” she says. “Behavior can help us understand treatment responses, patient well-being, and how emotions, cognition, and stress influence disease progression. It may also help improve therapeutic outcomes.”

In pursuit of better sleep

Chandra Jackson, an Earl Stadtman investigator at the National Institute of Environmental Health Sciences (NIEHS), leads groundbreaking research on the environmental and social determinants of sleep health. Her work identifies how factors like light exposure, temperature, and psychosocial stress affect sleep and, in turn, influence cardiometabolic health.

“I am interested in understanding the epidemiology of sleep health—the distribution across the population, determinants, consequences, and approaches to maintain or improve sleep according to our latest recommendations,” said Jackson. “Identifying exposure burdens, for instance, provides information needed to develop effective interventions.”

A core interest of Jackson’s research is the exposome, an initiative strongly supported by NIEHS that examines how environmental exposures affect health over a lifetime. She believes sleep health is an ideal model for exposomic research.

“Sleep is directly affected by many modifiable and non-modifiable exposures in our environment over the life course,” she explained. “These exposures also span the entire research spectrum from genetics to job strain to light pollution, and it will be interesting as well as important to investigate which modifiable exposures contribute the most to sleep problems using a more comprehensive approach. This [potential research] could inform personalized prevention and treatment strategies as well as broader environmental changes.”

By looking at sleep through an exposomic lens, Jackson aims to identify specific factors that can be modified to improve sleep. Her research seeks to integrate environmental, social, and biological factors, offering a comprehensive approach to studying this important process.

Jackson uses several large-scale epidemiological cohort studies with funding support by NIH, publicly available datasets used to monitor the health of the nation such as the National Health Interview Survey, and a network of community health data centers she has linked to environmental data. These large datasets allow her to look at the broad population in many cases, as well as differential burdens in exposures and health outcomes.

In sleep research, Jackson mentioned that the field is pushing for more accessible diagnostics, such as wearable devices or biological samples such as blood and saliva.

“Identifying objective, reliable, and accessible biomarkers for sleep and sleep-related conditions is a significant research focus with the potential to transform diagnosis, treatment, and monitoring,” she said, adding, “While the gold standard remains polysomnography, there’s a strong push for more convenient, less costly methods.”

Jackson also was senior author on a global call to action. This call, published in Lancet Public Health, recommends that organizations with public health priorities include sleep health. The authors note that decades of research across disciplines provide strong evidence that sleep is foundational for human health, just like physical activity and nutrition, and now is the time to begin leveraging sleep health to improve human health and wellbeing worldwide.

For Jackson, sleep is more than just going to bed at night. As she describes it, “Sleep has relevance to nearly all research questions, across disciplines, because it is a biological, psychological, and sociological necessity that intersects with nearly every domain of human function and behavior.”

A team science approach

Diane Putnick is a statistician at NICHD who is helping to shape a more holistic understanding of pregnancy, parenting, and child development by integrating the psychological, social, and biological factors that could improve outcomes for families. She also explores the factors that influence children’s mental health and development, from parental behavior and mental health to environmental and social factors.

“I am broadly interested in what makes kids happy and healthy,” Putnick said. This broad curiosity has led her to examine a variety of topics, including how neighborhoods, screen time, and parental mental health shape child development.

Putnick describes herself as an “oddball” within the NICHD intramural research program’s epidemiology branch, where she is the only psychologist working alongside a team of epidemiologists and other researchers. “Working with experts from different fields really strengthens our research,” she said. “For example, in the Study of Pregnancy and Neonatal Health (SPAN), we have a geneticist focused on fetal growth, a physician studying pregnancy health, an epidemiologist focused on paternal contributions to child health, and me, looking at psychological aspects. We are focused on [complementary] but different aspects of pregnancy and wellbeing.”

In SPAN, this diverse mix of investigators design studies and decide on data collection methods while ensuring all perspectives are considered. “It really helps when you have people with different expertise explaining why something is important to measure from their perspective,” Putnick added.

A complementary study to SPAN that Putnick is involved in is the Upstate KIDS Study. The Upstate KIDS Study is a birth cohort study following over 6,000 children for the first decade of life. This study provides valuable developmental data such as measures of relationship quality, of attachment to the pregnancy, and of in-depth feelings about the experience for both parents, though the study lacks comprehensive biological samples like those being collected in SPAN.

SPAN is focused on a comprehensive view of pregnancy and neonatal health, collecting biological samples such as placental tissue and blood as well as deeper behavioral data from participating families.

Putnick’s research is centered on mental health, particularly the role of depression in parents. SPAN will allow a deeper understanding of how paternal mental health affects pregnancy and child well-being.

“People often overlook how men are affected by pregnancy,” she said. “They also experience significant life changes, and studying paternal mental health can provide a fuller picture of family dynamics during pregnancy.”

Putnick aims for her findings to influence real-world practices. “Progress isn’t just about collecting data; it’s about making sure our research has a practical application,” she said. “The intramural research program spends a lot of time on biology, which is incredibly important. But I feel like we, as the intramural research community, could spend more time on how people think and feel. Psychological factors are tied to biology and disease response and all the things we study here.”

A new coordinating committee

OBSSR is establishing a coordinating committee to identify and advance high-priority, cross-cutting behavioral and social science topics, training opportunities, and common infrastructure needs within and across all ICs. OBSSR aims to provide support, facilitate information sharing, and maximize the impact of IRP research. All IRP investigators and trainees interested in behavioral and social sciences are welcome to be part of this new, NIH-wide community. Join the OD-NIH IRP-BSSR-CC Teams Channel (use code cbhy3p1). Send your input, questions, and comments to farheen.akbar@nih.gov.