An Early and Unequal Decline: Life Course Trajectories of Cognitive Aging in the United States.

Objectives: Cognitive aging is a lifelong process with implications for Alzheimer's disease and dementia. This study aims to fill major gaps in research on the natural history of and social disparities in aging-related cognitive decline over the life span. Methods: We conducted integrative data analysis of four large U.S. population-based longitudinal studies of individuals aged 12 to 105 followed over two decades and modeled age trajectories of cognitive function in multiple domains. Results: We found evidence for the onset of cognitive decline in the 4th decade of life, varying gender differences with age, and persistent disadvantage among non-Hispanic Blacks, Hispanics, and those without college education. We further found improvement in cognitive function across 20th century birth cohorts but widening social inequalities in more recent cohorts. Discussion: These findings advance an understanding of early life origins of dementia risk and invite future research on strategies for promoting cognitive health for all Americans.

Social Relationships, Wealth, and Cardiometabolic Risk: Evidence from a National Longitudinal Study of U.S. Older Adults.

Objectives: To investigate multiple dimensions of social relationships related to biomarkers of cardiometabolic health and how their associations vary by wealth in older adults. Methods: Growth curve models were used to investigate the longitudinal associations between measures of both positive and negative social relationships and cardiometabolic risk (CMR) over a 10-year period from 2006 to 2016 and the moderation of this association by wealth in the Health and Retirement Study (HRS). Results: Older adults with better social relationships had lower CMR on average. The protective effects of positive social relationships, however, waned at older ages, particularly for low-wealth individuals. Discussion: Our results suggest that good social relationships promote healthy aging by buffering against harmful cardiometabolic consequences of psychosocial stress, particularly among relatively wealthy individuals. Efforts to improve old age health would be more effective when focusing simultaneously on fostering social connections and boosting financial resources.

Do high school friends still matter for health behavior in adulthood? Variations in smoking trajectories by adolescent peer smoking networks, race/ethnicity, and gender.

Peers play an influential role in the initiation of smoking during adolescence. However, there has been limited literature examining whether adolescent peers are associated with longer-term patterns of smoking. This study uses data from the National Longitudinal Study of Adolescent to Adult Health to examine whether age-based trajectories of smoking likelihood from adolescence to adulthood are associated with the number of adolescent friends who smoked and how this association differs by race/ethnicity and gender. Findings using multilevel growth curve models indicate that individuals who have more adolescent friends who smoked have higher probabilities of smoking during adolescence than those with no adolescent smoking friends. As individuals age into adulthood, the association between adolescent friends' smoking behavior and individual-level smoking begin to dissipate but does not completely disappear. Further analyses show that there are no differences in this association by gender, but there are differences by race/ethnicity. These findings suggest that high school friends continue to be associated with trajectories of smoking even twenty years after high school. These results indicate that anti-smoking campaigns should take a network approach to preventing smoking in adolescence as well as recognize that the same campaign strategy may not work for all groups.

Understanding the Public's Intentions to Purchase and to Persuade Others to Purchase Antibiotic-Free Meat.

Extending the effectiveness of media-based campaigns into interpersonal networks has been a long concern for studies on persuasive messages, yet there is much to understand about why people attempt to persuade others to engage in health-related behaviors. This study investigated two alternative predictors of interpersonal persuasion: psychosocial determinants of behavior and homophily. We used the integrated model of behavior (IMB) to predict consumers' intentions to purchase antibiotic-free meat, and extended the model to predict consumers' intentions to encourage important others to do so. IMB variables predicted 44% of future purchasing intentions and 40% of future persuasion intentions. The findings support a homophily explanation for persuasion: people intend to persuade important others to do what they do. In addition, a person-centered analysis identified three audience segments based on antibiotic-resistance-related behaviors, cognitions, and experiences: Purchasers, Resisters, and New Adopters. The covariate analysis revealed that people who had more topic awareness of antibiotic use in animal husbandry, knowledge of someone with an antibiotic-resistant infection, and health mavenism were more likely to be Purchasers than Resisters or New Adopters. Anxiety, however, was highest among New Adopters and lowest among Resisters. Implications for theory and practice are discussed.