Femininity and fertility in sisters with twin brothers: prenatal androgenization? Cross-sex socialization?

Are sisters of twin brothers behaviorally or physiologically masculinized? Prenatal exposure to their brothers' androgens and postnatal socialization experiences unique to girls growing up with twin brothers might influence their attitudes, pubertal development, and reproductive histories. To investigate, we studied age- and cohort-matched samples of Finnish sisters from same-sex and opposite-sex twin pairs. Using data from two ongoing longitudinal studies of consecutive birth cohorts of Finnish twins, we assessed pubertal development at ages 11 and 14 and endorsement of attitudes associated with femininity at age 16. We also studied fertility in Finnish women from same- and opposite-sex twin pairs born from 1958 through 1971, obtaining information on their child-bearing histories when they were ages 15 to 28. Results of each comparison were unambiguously negative: There was no evidence of differences between sisters from same- and opposite-sex twin pairs, and thus, no evidence of either androgenization or cross-sex socialization.     

Role of attention, memory, and covariation-detection processes in clinically significant eating-disorder symptoms

Cognitive theorists implicate a role for cognitive processing of shape- and weight-related information in the maintenance and potential etiology of eating disorders. The present study examines the role of women’s processing of information regarding other women’s body size and affect in eating disorder symptoms among young women. 253 female undergraduates completed attention, memory, and covariation-detection tasks that presented full-body photographs of young women, as well as an eating-disorder measure. High-Symptom women, relative to Medium- and Low-Symptom women, showed greater relative attention to body size than affect, better memory for body size and worse memory for affect, and enhanced sensitivity to the manipulated covariation between body size and affect. All participants perceived an illusory correlation between body size and affect. These findings suggest that cognitive theories may be extended usefully by considering processing of other-relevant and affective information, as well as the role of covariation-detection processes in eating disorders.