Social Disparities and Health
Program

IPR’s Cells to Society (C2S): The Center on Social Disparities and Health continues to expand its scope of activities to understand how social, economic, and cultural contexts affect physical and mental health, as well as cognitive achievement at the population level. Faculty research overlaps with other IPR program areas, in particular Child, Adolescent, and Family Studies; Poverty, Race, and Inequality; and Education Policy. Developmental psychologist P. Lindsay Chase-Lansdale is C2S’ founding director. Currently, the center has three signature research themes:

Overview of Activities

Social Disparities, Stress, and Health

Add Health and Biomarkers
A team of C2S researchers is investigating the impact of socioeconomic status, social relationships, and neighborhood quality on biomarkers of health collected as part of the fourth wave of the National Longitudinal Study of Adolescent Health, also known as Add Health. Anthropologist Thomas McDade and developmental psychobiologist Emma Adam, the project’s lead investigators, helped design the biomarker protocols for the Add Health study, which includes a nationally representative sample of approximately 20,000 U.S. adolescents. The five-year project is the most comprehensive investigation to date of how social stressors influence adolescent physical and mental health. It is examining how stress can lead to health disparities and affect adult health outcomes. Additional C2S faculty members collaborating on the project include developmental psychologist P. Lindsay Chase-Lansdale and social psychologist Thomas D. Cook.

Laboratory for Human Biology Research
McDade directs the Laboratory for Human Biology Research at Northwestern, which also serves as home to C2S’ biomarker core. The laboratory works to refine methods for assaying biomarkers in a drop of blood collected on filter paper from a single finger prick. This method is helping to revolutionize how information can be collected in field-based settings to investigate physiological functions and health. Collecting the samples is relatively painless and noninvasive; samples do not have to be centrifuged, separated, or immediately frozen; and multiple assays can be performed from a single drop of whole blood. Some major longitudinal studies such as Add Health, the Mexican Retirement Survey, Health and Retirement Study, and Panel Study of Income Dynamics have begun using this technique to measure blood samples for evidence of health and physiological development, for example, examining markers of immune function and cardiovascular disease risk. McDade is Weinberg College Board of Visitors Research and Teaching Professor.

Laboratory for Culture and Health
C2S opened a second laboratory in its new administrative and laboratory space, the Laboratory for Culture and Health (LCH), directed by anthropologist Ryan Brown. LCH will investigate how culture affects the relationships among emotion, decision making, and biological reactivity and health. In collaborative work with Margaret Kemeny at the University of California, San Francisco, Brown finds that anger plays a protective role against pathological biological reactivity to social threat, while shame was associated with slower recovery of multiple biological systems (neuroendocrine and cardiovascular) to baseline levels. The laboratory’s current research efforts will focus on developing ecologically valid social stimuli for use across different cultural groups and constructing field techniques for large-scale studies.

Cultural Processes and Population Health
Brown seeks to measure cultural processes in large epidemiological studies with relevance for population health. Much of this work involves the Great Smoky Mountains Study, a large-scale longitudinal study of families and health in North Carolina’s Appalachian Mountains that Brown has been involved with since 2000. He uses a mixed-methods approach—qualitative and quantitative—with this sample, yielding insights on topics ranging from the developmental determinants of life goals and priorities to the role of masculinity and social change in generating risk for crystal methamphetamine use. Brown also collaborates with demographers and economists on how historical processes and complex social events influence life expectancy.

Acculturation and Risk-Taking
First-generation Latino and Asian immigrant youth initially exhibit less risky health behaviors than U.S.-born youth, yet this “protective effect” disappears or reverses as their acculturation increases. Collaborating with Bonnie Halpern-Felsher at the University of California, San Francisco, Brown is exploring the cultural and emotional mediators of the “acculturation gradient” in risk-taking in two California high schools. Recently, Brown developed and administered a survey instrument to assess the relationship between race-ethnicity, acculturation, and risk-taking behavior in a nationally representative and multiethnic sample of 600 U.S. youth. Initial analyses indicate that large cultural differences in the perceived chances of family and community shame mediate group differences in risk-taking behaviors.

Health Disparities and Child Development
Phase II of the Community Child Health Network started in spring 2008 at five U.S. sites. The Illinois site, Community Action for Child Health Equity (CACHE), is a partnership between Northshore University Health System and the Lake County Health Department’s community health centers. CACHE explores how community, family, and individual influences interact with biological influences, resulting in disparities in perinatal health outcomes and infant and early childhood mortality and morbidity. Its theoretical model and research design emphasize the potential impact of social and economic environments on physiological stress and health in mothers and fathers during the pregnancy and the interpregnancy period. Pediatrician Madeleine Shalowitz is co-principal investigator, and several C2S and IPR faculty—developmental psychologists Emma Adam and P. Lindsay Chase-Lansdale, pediatrician Craig Garfield, anthropologists Christopher Kuzawa and Thomas McDade, and statistician Bruce Spencer—are involved.

National Children’s Study
Pediatrician Jane Holl leads the Chicago site of the National Children’s Study, which is recruiting and following 2,000 children in DuPage, Will, and Cook counties. It is part of the largest study of child health and well-being ever conducted in the United States and will eventually include more than 100,000 children from 107 U.S. sites. The study is assessing a wide range of environmental and genetic factors on pregnant women, children, and adults. Its goal is to prevent and treat some of the nation’s most serious health problems, including autism, birth defects, diabetes, heart disease, and obesity. Combining analyses of blood, urine, and hair with field observations, study researchers hope to examine how factors like food intake, air and water quality, neighborhood safety, and quality of medical care affect participants. Researchers also plan to look at children’s possible exposure to chemicals from materials used to construct their homes and schools.

Families, Intrapersonal Relationships, and Health

Stress and Teen Depression
Adolescent depression is a major health issue that affects approximately 15 to 20 percent of all U.S. adolescents at some point. In a four-year longitudinal study, Daily Experiences, Stress, and Sleep over the Transition to Adulthood, Adam and her colleagues are exploring how exposure to stress affects the development of depression and anxiety in adolescents as they move from high school to college or a job. Adam uses interviews, questionnaires, and diaries to capture their transition experiences. By measuring the stress hormone cortisol and sleep quality using wristwatch-sized “actigraphs,” she is trying to trace the physiological impact of these changes. Annual clinical interviews diagnose depression and anxiety disorders.

In a recent article, Adam and her colleagues reviewed the current state of research on the role of HPA axis functioning—which can be measured through a person’s cortisol levels—to predict, and guide treatment of, adolescent depression. While the researchers find great promise for using HPA axis indicators, measures of it in clinical settings are rare, and thus it does not yet constitute an accurate clinical tool. They call for more research into HPA axis measures and formulate a model to guide researchers in including such measures in prevention studies of adolescent depression. In this and other studies, Adam shows how daily measurements of cortisol can provide insights into how everyday social environments affect physiological stress levels in children and adolescents. She points to risk factors for negative health outcomes and possible interventions for them.

Effects of Parenting Styles on Youth
Jelani Mandara, a developmental psychologist, is examining the effects of parenting styles on the academic achievement, sexual activity, and behavioral problems of African American, European American, and Latino youth. Using data from the National Longitudinal Survey of Youth, Mandara is finding that girls and boys are parented differently by African American mothers. Girls are assigned more responsibilities and rules, for example, while boys are given more latitude. This is especially the case when the girl is the oldest child and the boy is the youngest. Mandara shows how this differential socialization might explain some of the reasons why African American males have such high rates of risky behaviors, incarceration, and school failure compared with females. He proposes interventions that teach African American parents authoritative parenting styles and how to treat boys and girls and younger and older siblings the same.

Romantic Attraction
Psychologist Eli Finkel continues his physiological study of initial romantic attraction in real-life interactions between potential romantic partners, supported by C2S seed-grant funding. Specifically, he is exploring biomarkers associated with two of three systems composing the experience of initial romantic attraction: lust and infatuation. He is also exploring individuals’ physiological stress responses to meeting and interacting with a series of potential romantic partners at speed-dating events. He and Northwestern psychologist Paul Eastwick have pointed out that such events are ideal for researchers to study romantic dynamics—and many other social dyads—because individuals are together in the same place at the same time in a situation with strong external validity. Finkel, Eastwick, and psychologist Jennifer Richeson are also working on a study of how political orientation moderates romantic desire in interracial relationships.

Longevity, Mortality, and Preconception-to-Adult Models of Health

Longevity in Latin America, the Caribbean
Alberto Palloni, Board of Trustees Professor in Sociology, is producing life expectancy projections for Latin America and the Caribbean with Mary McEniry of the University of Wisconsin–Madison and postdoctoral fellows Malena Monteverde and Kenya Noronha. They are investigating how growing rates of obesity and diabetes and the changing nature of the elderly cohorts might contribute to decreases in longevity in the region. They take into account the role of early childhood conditions, illness, and the influence of income and wealth.

In a recent study of 15,000 elderly people in Mexico and the Caribbean, Palloni and his co-authors find strong evidence that experiencing infectious diseases, poor socioeconomic status, and/or malnutrition before the age of 15 increases the risk of disability at older ages, in particular for vascular diseases. Palloni is also completing the first volume of a two-volume series, “Population and Society in Latin America: 1900–2000,” that will deal with health and mortality in the region.

Palloni and his collaborators are also using U.S. and Mexican data sets to study the Hispanic Paradox, in which U.S. Mexican immigrants have better levels of health than expected given their low income and educational status. The researchers are comparing the health status of Mexicans who immigrate to the United States to Mexicans who live in Mexico, focusing on mortality and socioeconomic health gradients.

Linking Childhood Health to Adult Outcomes
Are higher income, wealth, education, and occupation protective of health? Are social strata endowed with characteristics that lead to health enhancement or health deterioration? Or is it possible that through complex processes, individuals who are predisposed to poor health early on are also less likely to acquire the skills to climb the social ladder and thus more affected by the earlier onset of ill health? With Carolina Milesi of the Population Research Center at the University of Chicago/NORC, Palloni has launched a multifaceted research program combining six national data sets to examine how to empirically link socioeconomic attainment and adult health across the lifecourse. In their project, the researchers hope to document the impact of early health conditions on adult SES and health outcomes, determine whether acquired skills and traits can mediate the impact of early health conditions on adult outcomes, and examine the degree to which early health conditions could explain adult health disparities.

Globalization and Health Outcomes
IPR/C2S faculty are interested in how globalization affects health outcomes, and faculty members have been part of two ongoing studies: the Tsimane’ Amazonian Panel Study in Bolivia and the Cebu Longitudinal Health and Nutrition Survey in the Philippines. Both are rich resources for studying the long-term health effects of early environments and might provide additional insight on domestic health outcomes.

The Cebu Survey has followed more than 3,000 mothers who were pregnant in 1983 and their children, who are now young adults and having children of their own. Working with U.S. and Filipino collaborators, anthropologist Christopher Kuzawa studies the influence of fetal/infant nutrition and growth on adult health and function in the Philippines. Three extensions of the study are underway. The first uses 22 years of longitudinal data to investigate predictors of metabolic disease risk factors in the mothers and their young adult offspring. The second combines these data with saliva and plasma samples to examine if early life nutrition affects adult male reproductive functioning, A third follows up with the original offspring, now adults with children of their own, and looks at the intergenerational influences on offspring nutrition and growth. The National Science Foundation supports the latter two projects.

Using plasma samples from 1,875 Filipino women participating in the Cebu study, McDade and Kuzawa, with IPR postdoctoral fellow Julienne Rutherford and Linda Adair of the University of North Carolina at Chapel Hill, examined how obesity and infectious agents affected the women’s levels of C-reactive protein (CRP). Elevated levels of CRP can indicate the presence of cardiovascular disease (CVD), hypertension, and diabetes. Their data indicate that being overweight or obese and exposed to infectious diseases are associated with elevated CRP levels, and these associations are not linked to socioeconomic status or other health behaviors. Their findings also indicate that other cultures transitioning to high-calorie, Western-style diets with lower levels of physical activity are also experiencing comparable levels of elevated inflammation, probably contributing to the worldwide epidemic of CVD and metabolic diseases. The findings were presented at the Population Association of America meetings in April 2008 and appeared in three new articles published in the Journal of Nutrition and American Journal of Clinical Nutrition.

Childhood Growth and Adult Outcomes
The Tsimane’ study links the effects of globalization to health and early developmental conditions to later outcomes. In a study led by McDade, the researchers identify significant costs associated with activation of immune defenses to growth among children in a remote area of Amazonian Bolivia. They find that young Tsimane’ children (aged 2 to 4) with low body fat stores might lose 10 to 15 percent of their expected annual height gain. Such stunted growth is associated with reduced work capacity and poorer reproductive outcomes in adulthood, as well as increased mortality risk.

In another study, Kuzawa, McDade, and their co-authors are the first to find evidence for changes in the relationship between leptin, a hormone that seems to signal energy intake and expenditure, and body fat during childhood growth and development. In males, there was a small relationship between body fat and the hormone, while in females the correlation between the two increased markedly as they approach puberty. The correlation suggests a more important role for leptin as a signal of energy status in females, perhaps indicating a larger effect on female development and reproduction.

Intergenerational Model of Health Disparities
Kuzawa is exploring the application of an intergenerational model of biology and health to the problem of U.S. health disparities. He and graduate student Elizabeth Sweet published a model of the environmental origins of health disparities in cardiovascular disease (CVD) between U.S. whites and blacks. They review evidence linking stressors within the African American community, such as discrimination, with maternal stress during pregnancy—leading to poorer birth outcomes, such as lower birth weights, and a higher risk of CVD among adult offspring. They argue that the embodiment of negative socio-environmental factors in the prenatal environment provides a better explanation than genetics for the biological persistence of disease disparities. While they recognize that legislation cannot directly address certain contributors, they point to social policies, such as better access to prenatal care and promoting breast feeding, that could mitigate patterns of U.S. health disparities in future generations.

Genetics and the Social Sciences
Sociologist Jeremy Freese continues to pursue the place of sociology in interdisciplinary research that spans social, psychological, and biological analyses within the context of social and technological change. In a special issue of the American Journal of Sociology exploring genetics and social structure, Freese provides a basic theoretical statement for sociologists about the centrality of psychological constructs in drawing explanatory relations between genetics and social outcomes, as well as in describing how the causal potency of genes carries across social contexts. Freese argues that social scientists will not be thrown out of work in the coming years by increased understanding of the biological mechanisms of genomic causation. Genomic causation is not in competition with social conditions, but a product of them, Freese explains. Thus, sociologists will be needed to provide explanations for why genetic differences are more—or less—relevant to individual outcomes.

Controlling the Expression of Prejudice
In psychologist Jennifer Richeson’s study of how people control the expression of prejudice, she explores how individuals’ concerns about either being or appearing racially biased influence subtle aspects of cognition, emotion, and behavior. She directs Northwestern’s Social Perception and Communication Laboratory, which seeks to better understand the effects of diverse environments on individuals’ feelings and behavior and to investigate the antecedents and consequences of prejudice and stereotyping.

Using a dot-probe detection paradigm and photos of black and white individuals with either a neutral or happy facial expression, Richeson and C2S postdoctoral fellow Sophie Trawalter tested the selective attention of white individuals who are highly motivated to avoid appearing prejudiced toward blacks. Their study reveals that the white participants are drawn to black faces with neutral expressions when exposed for 30 milliseconds and avert their gaze when shown the same neutrally expressive black faces for longer (450 ms). Smiling black faces eliminated the attentional bias altogether. Their results, published in Psychological Science, indicate that pressure to avoid appearing prejudiced leads to anxious reactions and threat responses to out-groups. Their study indicates a new direction for future research on racial bias and holds implications for building a harmonious, multiracial society.

Negative Group Stereotypes, Stigmatization
Many companies, schools, and other organizations strive to increase their diversity, yet how do stigmatized individuals fare within them? Richeson is examining the experiences of racial minorities and members of other low-status groups as they attempt to persist—and even succeed—in the face of low numbers and negative group stereotypes. Specifically, Richeson is investigating the extent to which racial minority and low-SES students at a predominantly white private university engage in “covering”—a compensatory form of self-regulation that surfaces in managing a stigmatized identity—when they feel their group identity threatened and/or they feel they are the targets of prejudice. She is also tabulating potential intrapersonal costs of covering, including physiological stress reactions, feelings of inauthenticity and shame, increased loneliness, and cognitive depletion.

Racial Bias and Mental Illness
Richeson and Nicole Shelton of Princeton University are exploring whether racial bias constitutes a risk factor for mental disorders (namely depression) among African Americans and Latinos. Specifically, their work considers the effects of subtle—as compared with blatant—expressions of racial discrimination during interpersonal interactions in the development of mental disorders. They also consider how suppressing emotional reactions to interpersonal discrimination can affect mental disorders and examine whether the stigma of mental illness operates in a similar manner to racial bias in one-on-one interactions. The National Institute of Mental Health and the Office of Behavioral and Social Sciences Research provide project funding.

Oncofertility
The Oncofertility Consortium, a national research, clinical, and education program led by oncofertility researcher Teresa Woodruff, brings physicians, medical ethicists, social scientists, and basic scientists together to develop new strategies for fertility preservation for female cancer survivors. They are developing an experimental technique that uses emergency in-vitro fertilization (IVF) to store ovarian tissue for future conception before girls and women undergo cancer treatment. After one ovary is removed and cryopreserved, or frozen, immature follicles are extracted and matured in the lab so that they can later be fertilized. McDade is currently working on a related project to develop a minimally invasive method for assessing ovarian reserve. Woodruff, Thomas J. Watkins Memorial Professor of Obstetrics and Gynecology, is also director of the Division of Fertility Preservation, which is establishing the first “follicle bank” for U.S. cancer survivors. She directs one of the National Institutes of Health’s specialized cooperative centers in reproduction research.

Evolution of Biological Knowledge
Psychologists Sandra Waxman and Douglas Medin of Northwestern are currently writing a book about their research on the evolution of biological knowledge and reasoning across cultures and across development. They led an interdisciplinary research team of psychologists, linguists, and anthropologists who interviewed young children and adults from a wide range of language and cultural communities. The participants included urban and rural U.S. English speakers from majority culture and Native American populations. Their research offers evidence of strong universal patterns in most fundamental notions of the natural world. It also highlights striking differences that illuminate intimate connections among culture, language, and the organization of knowledge. In a recent experiment with Florencia Anggoro of Georgia State University, they ask 4- and 9-year old English- and Indonesian-speaking children to identify various entities as “alive.” Older Indonesian speaking children selected both plants and animals, but their English-speaking counterparts tended to exclude plants. This suggests a misalignment in meaning for the English speakers with one of the ‘‘animal’’ senses.

Is Race Biological?
Intrigued by a resurgence of scientific interest in race-based genomic variation and the use of racial categorization in biomedicine, law professor Dorothy Roberts, Kirkland & Ellis Professor, investigates the expansion of race consciousness in biomedical research and technologies in its sociopolitical context to determine how it is related to race consciousness in social policies. Drawing on her larger study of race consciousness in biotechnology, law, and social policy, including interviews of 30 scientists, activists, and bioethicists, Roberts is exploring how experts are redefining the scientific meaning of race and its relationship to biology in both illuminating and inconsistent ways. Funding for the project comes from the National Science Foundation and Robert Wood Johnson Foundation.

Screening for Cardiovascular Disease
Given the availability of today’s technology to measure the functioning of the human heart, should there be routine screening to check for cardiovascular disease (CVD)? Commenting in the Journal of the American College of Cardiology, cardiologists Philip Greenland and Donald Lloyd-Jones advised against adopting a routine strategy for CVD screening. They point to limited evidence that current screening procedures, which carry varying amounts of risk and harm for patients, cannot accurately predict CVD in asymptomatic individuals. They call for more research to justify implementation of a policy to systematically conduct population-level screenings for CVD. Greenland is Harry W. Dingman Professor and executive associate dean for clinical and translational research at Northwestern.

Biomarker Training
A nationally recognized center of biomarker training and methodological development, C2S held its third summer biomarker institute from June 9 to 11, welcoming 28 participants. The three co-organizers—McDade, Adam, and Kuzawa—emphasized biological theory and methodology in this year’s session with a daylong introduction to biology’s role in the social sciences, in addition to hands-on training on salivary and blood spot biomarkers. Freese led a module on the integration and analysis of genetic data into survey research.

Colloquium Series
C2S has continued its efforts to foster a community of scholars interested in multidisciplinary research on how social, economic, and cultural factors “get under the skin” and influence the pathways and processes of human development, health, and well-being. To this end, C2S brings researchers and practitioners together through its colloquia. Six talks were held on topics, such as the epidemiological evidence for obesity and sleep by Diane Lauderdale of the University of Chicago.

Health and Attainment Over the Lifecourse
More than 100 researchers, policymakers, foundation leaders, and postdoctoral and doctoral students attended the May 16 conference “Health and Attainment Over the Lifecourse: Reciprocal Pathways from Before Birth to Old Age.” The conference brought together experts from diverse disciplines to address complex linkages between health and human capital over time. Both are seen as lifelong processes, but too often, research on attainment and health has developed in separate silos. Scholars from demography, anthropology, sociology, economics, developmental psychology, and molecular genetics participated, including several C2S faculty. C2S was co-sponsor of the conference.

Seed Grant Program
C2S awarded six seed grants over the academic year to the center’s tenure-track and research faculty for projects integrating the social sciences with the life or biomedical sciences. In March 2008, the center also launched a Student Research Grant program for students conducting dissertations or doing postdoctoral research.

New Graduate Training Program
Northwestern Graduate School’s Interdisciplinary Cluster Initiative recently provided funding for a graduate training program in society, biology, and health in conjunction with C2S. The program
will allow graduate students to pursue a formalized course of study on the topic starting in 2009–10 with 19 faculty affiliates. Led by McDade, the cluster is aligned with C2S initiatives and will provide a roadmap for graduate students in the quantitative social sciences who are interested in integrative, community-based research on human biology and health.

Postdoctoral Fellows and Graduate Students
C2S’ first postdoctoral fellows have graduated and obtained key positions in postdoctoral fellowship programs or as faculty members. Sophie Trawalter, who studies racial interaction and student stress and development, will join the University of North Carolina at Chapel Hill in July 2008 as an assistant professor of psychology. Julienne Rutherford, an anthropologist who studies the role of the placenta in maternal ecology, fetal development, and health outcomes, will take up a position as an assistant professor at the University of Illinois at Chicago in August 2009. Elizabeth Sweet, who obtained her PhD in anthropology, became a Robert Wood Johnson Health and Society Fellow at Harvard University in fall 2008. Laura Chyu, who holds a PhD in public health from the University of California, Los Angeles, joined C2S in fall 2008 as a postdoctoral fellow. She is examining how the dynamic interplay of biological and social factors affects health over the lifecourse. Graduate student Chelsea McKinney, who is completing her doctorate in human development and social policy, was awarded an NICHD Diversity Supplement.