In response to the recent publication and media coverage of several books that support educating boys and girls separately, more public schools in the United States are beginning to offer same-sex schooling options. Indeed, students may be more comfortable interacting solely with same-sex peers, as boys and girls often have difficulty in their interactions with each other; however, given that boys and girls often interact beyond the classroom, researchers must discover why boys and girls suffer difficult other-sex interactions and determine what can be done to improve them. We present two studies aimed at examining such processes. Both studies were conducted from a dynamical systems perspective that highlights the role of variability in dyadic social interactions to capture temporal changes in interpersonal coordination. The first focused on the utility of applying dynamics to the study of same- and mixed-sex interactions and examined the relation of the quality of those interactions to participants' perceptions of their interaction partners. The second study was an extension of the first, examining how dynamical dyadic coordination affected students' self-perceived abilities and beliefs in science, with the intention of examining social predictors of girls' and women's under-representation in science, technology, engineering, and mathematics.

The adaptation and integration of the mainstream and ethnic culture are important processes to understand as they have been associated with immigrant and minority youth's adjustment and family dynamics. However, few studies focusing on youth's cultural experiences have explored youth's active role in their own cultural development, and even less have explored youth's role in influencing parents' cultural development. In the current dissertation, two studies addressed these issues by using a within-family longitudinal design to explore 246 Mexican American youth's role in their own and their families' cultural development. The first study examined the reciprocal associations in parents' and two offspring's cultural values to examine developmental differences in parent-youth socialization processes. Overall, the importance of mothers' values was highlighted as a significant predictor of increases in youths' values, five years later. In addition, Study 1 highlighted situations where youth play an active role in their parents' cultural development as youths' lower endorsement of respect for elders values was associated with increases in fathers' value endorsement, five years later. The second study explored the associations between youth's imitation and de-identification from parents and parent-youth incongruence in Mexican and Anglo cultural orientations. Youths' active role in their cultural development was underscored, as youths' reports of de-identifying from parents were linked to more incongruence in parent-youth Anglo orientations. Further, important family characteristics (i.e., parent-youth warmth and demographic similarities) were shown to predict youths' more imitation and less de-identification from parents.

In the present research, elements of the intra- (i.e., family dynamics) and extra-family (i.e., characteristics of parents' occupations) contexts were examined in a longitudinal design as associated, broadly, with individuals' mental health, relationship quality, and future orientations among Mexican American families with adolescent offspring in two separate studies. The first study reviewed the utility of applying dyadic data methods to the investigation of family processes, explored the strengths three different analytic approaches (i.e., the actor-partner interdependence model, a two-intercept model, and a difference model), and applied them to the study of marital relationships (N = 246 marital dyads). Results revealed that spouses' marital negativity was related to their own somatic symptoms, whereas, spouses' somatic symptoms were associated with both their own and their partners' marital negativity, with some variations by approach. This study suggested the three analytic approaches, though designed to answer slightly different questions, yielded a similar pattern of results with several important differences. The second study utilized a person-centered approach to identify family-level patterns of both mothers' and fathers' objective occupational characteristics (i.e., self-direction, hazardous conditions, physical activity), as well as the larger sociocultural context of these patterns (N = 160 dual-earner families). Results revealed three distinct occupational contexts: Differentiated High Physical Activity, Incongruent, and Congruent High Self-Direction. Results indicated that families in the Congruent High Self-Direction profile had the highest levels of youth career aspirations, whereas, educational aspirations were the highest among youth in both the Incongruent and Congruent High Self-Direction profiles. Youth-mother and -father conflict was highest in the Congruent High Self-Direction profile, and youth-father warmth was highest for families in the Differentiated High Physical Activity profile. This study suggested that Mexican American parents work in varied occupational contexts, and these contexts were differentially associated with family relationships and youth's orientations toward the future.

Growing concern about obesity prevalence among youth has prompted the examination of socio-environmental influences that shape the development of eating and activity behaviors believed to regulate weight. Given the presumed significance of close friendships during adolescence, the present investigation assessed longitudinal relations between friends' physical activity, sedentary activity, and healthy eating behaviors and explored whether friends' obesity-promoting behaviors are linked to heightened obesity risk among adolescents. This prospective study utilized two Waves of data from 862 reciprocal and 1908 nonreciprocal same-sex friend dyads participating in the National Longitudinal Study of Adolescent Health. To account for nonindependence tied to membership in a particular friendship dyad, multi-level models were estimated for indistinguishable (i.e., reciprocal) and distinguishable (i.e., nonreciprocal) friend pairs using the Actor Partner Interdependence Model. Adolescents' self-reported physical activity and healthy eating were significantly associated with their own and their friends' physical activity and healthy eating one year later; the strength of socialization across friend dyads did not vary with the frequency of interaction between friends or the stability of friendships over time. Limited support was found for a cumulative risk model of obesity-promoting behaviors as a predictor of increased obesity risk; heightened risk for weight gain was found only for adolescents whose reciprocal same-sex friends reported a higher number of obesity-promoting eating and activity behaviors. Overall, study findings highlight the role of close friends for adolescents' obesity risk and obesity-related behaviors. Stronger evidence of socialization resulted for adolescents that perceived their friends to be salient social models, as reflected by their acknowledgement of an existing friendship with such peers (i.e., reciprocal friends and nominators within nonreciprocal friend dyads).