Robert Crosnoe

The Emergence and Development of Life Course Theory

Today, the life course perspective is perhaps the pre-eminent theoretical orientation in the study of lives, but this has not always been the case. The life histories and future trajectories of individuals and groups were largely neglected by early sociological research. In the pioneering study, The Polish Peasant in Europe and America (1918-1920), W. I. Thomas (with Florian Znaniecki) first made use of such histories and trajectories and argued strongly that they be investigated more fully by sociologists. By the mid-1920s, Thomas was emphasizing the vital need for a “longitudinal approach to life history” using life record data (Volkart, 1951, p. 593). He advocated that studies investigate “many types of individuals with regard to their experiences and various past periods of life in different situations” and follow “groups of individuals into the future, getting a continuous record of experiences as they occur.” Though this advice went unheeded for decades, Thomas’s early recommendations anticipated study of the life course and longitudinal research that has become such a central part of modern sociology and other disciplines.

Identifying Risk for Obesity in Early Childhood

OBJECTIVES. Our aim with this study was to assist clinicians by estimating the predictive value of earlier levels of BMI status on later risk of overweight and obesity during the middle childhood and early adolescent years. METHODS. We present growth data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, a longitudinal sample of 1042 healthy US children in 10 locations. Born in 1991, their growth reflects the secular trend of increasing overweight/obesity in the population. Height and weight of participating children in the study were measured at 7 time points. We examined odds ratios for overweight and obesity at age 12 years comparing the frequency with which children did versus did not reach specific BMI percentiles in the preschool- and elementary-age periods. To explore the question of whether and when earlier BMI was predictive of weight status at age 12 years, we used logistic regression to obtain the predicted probabilities of being overweight or obese (BMI ≥85%) at 12 years old on the basis of earlier BMI. RESULTS. Persistence of obesity is apparent for both the preschool and elementary school period. Children who were ever overweight (>85th percentile), that is, ≥1 time at ages 24, 36, or 54 months during the preschool period were >5 times as likely to be overweight at age 12 years than those who were below the 85th percentile for BMI at all 3 of the preschool ages. During the elementary school period, ages 7, 9, and 11 years, the more times a child was overweight, the greater the odds of being overweight at age 12 years relative to a child who was never overweight. Sixty percent of children who were overweight at any time during the preschool period and 80% of children who were overweight at any time during the elementary period were overweight at age 12 years. Follow-up calculations showed that 2 in 5 children whose BMIs were ≥50th percentile by age 3 years were overweight at age 12 years. No children who were <50th percentile for BMI at all points during elementary school were overweight at age 12 years. Children who have higher range BMIs earlier, but not at the 85th percentile, are also more likely to be overweight at age 12 years. Even at time points before and including age 9 years, children whose BMIs are between the 75th and 85th percentile have an ∼40% to 50% chance of being overweight at age 12 years. Children at 54 months old whose BMIs are between the 50th and 75th percentile are 4 times more likely to be overweight at age 12 years than their contemporaries who are <50th percentile, and those whose BMIs are between the 75th and 85th percentile are >6 times more likely to be overweight at age 12 years than those <50th percentile. CONCLUSIONS. The data from this study indicate that children with BMIs >85th percentile, as well as with BMIs in the high reference range are more likely than children whose BMI is <50th percentile to continue to gain weight and reach overweight status by adolescence. Pediatricians can be confident in counseling parents to begin to address the at-risk childs eating and activity patterns rather than delaying in hopes that overweight and the patterns that support it will resolve themselves in due course. Identifying children at risk for adolescent obesity provides physicians with an opportunity for earlier intervention with the goal of limiting the progression of abnormal weight gain that results in the development of obesity-related morbidity.

Intergenerational Bonding in School: The Behavioral and Contextual Correlates of Student-Teacher Relationships

To explore the significance of social integration in the educational system, this study examined whether student-teacher relationships predicted two important student behavioral outcomes (academic achievement and disciplinary problems); whether these within-school intragenerational relationships were predicted by the structural, compositional, and climate-related characteristics of schools; and how the behavioral and contextual correlates of student-teacher relationships varied by race-ethnicity. Our findings, based on nationally representative panel data, indicated that stronger intergenerational bonding in school was associated with higher academic achievement, especially for Hispanic American girls, and with a lower likelihood of disciplinary problems, especially for white girls. Moreover, these intragenerational bonds were stronger in schools with several characteristics (private sector, greater racial-ethnic matching between students and the student body, greater perceived safety, and lower socioeconomic status), although these associations also differed by race-ethnicity.

ADOLESCENT FRIENDSHIPS AS ACADEMIC RESOURCES: THE INTERSECTION OF FRIENDSHIP, RACE, AND SCHOOL DISADVANTAGE

Research on adolescent friendships has typically treated these social ties differently from friendships at other stages of life or from other relationships during adolescence. To draw parallels among these literatures, this study focuses on two largely neglected aspects of adolescent friendships: their role in positive adjustment and the way in which this role varies by social structural and institutional context. In an analysis of data from 9,223 adolescents in the National Longitudinal Study of Adolescent Health, we found that those who had friends who liked school or did well in school had fewer academic problems than did those whose friends were less academically oriented. This potential protective role of friends did not differ by race, but it did differ by level of school disadvantage. Moreover, this moderating role of school disadvantage differed by race. These results suggest that adolescent friendships serve as social capital, the value of which is context-specific.

Friendships in Childhood and Adolescence: The Life Course and New Directions*

Contemporary sociologists and psychologists have long been interested in youth friendship, and have generated a large but disconnected body of literature on this topic. In this essay, I advocate using life course theory to weave together the varied elements of this literature and to generate new lines of research for the next millennium. First, I survey four general themes of contemporary research: friendship and development, the nature and structure of friendship, friendship culture, and the social context of friendship. Second, I explore how life course theory can bridge sociological and psychological research by viewing friendship as shaped by sociohistorical forces and as regulating human development. Four general issues are discussed: pathways and trajectories, the social embeddedness of relationships, long-term perspectives on friendship, and methodological issues pertinent to life course treatments of friendship. By drawing on life course principles, future researchers can advance understanding of the role of friendship in young peoples lives.

Body Mass Index, Academic Achievement, and School Context: Examining the Educational Experiences of Adolescents at Risk of Obesity∗:

Reflected self-appraisal suggests that individual functioning is related to the fit between individual characteristics and the norms of their primary contexts. To apply this social psychological concept to the study of obesity, we hypothesized that adolescents at risk of obesity would have lower academic achievement overall than other students, especially in schools in which their weight status was most likely to elicit negative evaluations. Multi-level modeling of nationally representative data revealed that the negative longitudinal association between risk of obesity and achievement was stronger in schools with higher rates of romantic activity and lower average body size among students, two school contexts in which obesity was likely to be stigmatized, but weaker in schools with higher rates of athletic participation, a school context in which such stigmatization was also likely. Additional analyses suggested that this last, unexpected finding reflected a process of niche-picking.

Family Dynamics, Supportive Relationships, and Educational Resilience During Adolescence

If problematic relationships with parents are an academic risk factor during adolescence, then nonparental sources of support (e.g., friends, siblings, and teachers) may be arenas of comfort that promote educational resilience in the face of such risk. In a series of structural models using the National Longitudinal Study of Adolescent Health, the authors found that nonparental relationships are more likely to be directly associated with academic behavior than to interact with parent-related risk. Protective interactions occur only among certain subgroups. For example, close relationships with teachers and involvement with friends protect against parent-related academic risk among Asian American adolescents, whereas support from friends operates similarly for younger girls. In other subgroups, parental and nonparental relationships interact but not in a protective way. These patterns demonstrate the complex interplay of developmental ecology and larger social structures during the adolescent stage of life as well as the context-specific nature of resilience.

Double Disadvantage or Signs of Resilience? The Elementary School Contexts of Children From Mexican Immigrant Families

Children from Mexican immigrant families represent one of the fastest-growing populations in the American educational system, but their ability to use this system to improve their long-term prospects may be hampered by problems associated with their schools. The present study explored this issue in a national sample of American kindergarteners. First, propensity score matching techniques revealed that children from Mexican immigrant families were overrepresented in schools with a wide variety of problematic characteristics, even when family background differences were taken into account. Second, multilevel models revealed that the mathematics achievement, mental health, and interpersonal functioning of these children were often at lower levels in such schools. Studies such as the present investigation demonstrate the value of developmental models of inequality and can inform policy by identifying points of intervention.

Low-Income Students and the Socioeconomic Composition of Public High Schools

Increasing constraints placed on race-based school diversification have shifted attention to socioeconomic desegregation. Although past research suggests that socioeconomic desegregation can produce heightened achievement, the “frog pond” perspective points to potential problems with socioeconomic desegregation in nonachievement domains. Such problems are important in their own right, and they may also chip away at the magnitude of potential achievement benefits. In this article, I report conducted propensity score analyses and robustness calculations on a sample of public high schools in the National Longitudinal Study of Adolescent Health. As the proportion of the student body with middle- or high-income parents increased, low-income students progressed less far in math and science. Moreover, as the proportion of the student body with middle- or high-income or college-educated parents increased, low-income students experienced more psychosocial problems. Such patterns were often more pronounced among African American and Latino students. These findings suggest curricular and social psychological mechanisms of oft-noted frog pond effects in schools and extend the frog pond framework beyond achievement itself to demographic statuses (e.g., race/ethnicity and SES) perceptually linked to achievement. In terms of policy, these findings indicate that socioeconomic desegregation plans should also attend to equity in course enrollments and the social integration of students more generally.

Family Socioeconomic Status and Consistent Environmental Stimulation in Early Childhood

The transition into school occurs at the intersection of multiple environmental settings. This study applied growth curve modeling to a sample of 1,364 American children, followed from birth through age 6, who had been categorized by their exposure to cognitive stimulation at home and in preschool child care and 1st-grade classrooms. Of special interest was the unique and combined contribution to early learning of these 3 settings. Net of socioeconomic selection into different settings, children had higher math achievement when they were consistently stimulated in all 3, and they had higher reading achievement when consistently stimulated at home and in child care. The observed benefits of consistent environmental stimulation tended to be more pronounced for low-income children.