• Physical Correlates of Sexual Orientation: The Association of Height, Birth Weight, and Facial Structure with Sexual Orientation.

      Skorska, Malvina N.; Department of Psychology
      Researchers have examined whether certain physical characteristics are associated with sexual orientation to gain insight into the mechanisms that may be implicated in its development. Three relatively new and/or understudied physical correlates (height, birth weight, facial structure) were investigated to determine whether they are reliably associated with sexual orientation and to gain insight into the specific mechanism(s) that may be driving the association between these physical correlates and sexual orientation. In Study 1, gay men were found to be shorter, on average, than heterosexual men in a nationally representative US sample. There was no significant height difference between lesbian and heterosexual women. No evidence was found that stress and nutrition at puberty mediated the association between sexual orientation and height in men. Thus, other mechanisms (e.g., prenatal hormones, genetics) likely explain the sexual orientation-height link. In Study 2, firstborn gay male only-children had, on average, a significantly lower mean birth weight than firstborn children in four other sibship groups. There was also evidence of increased fetal loss among mothers of gay male only-children. Birth weight and fetal loss have been shown to be indicators of a mother’s immune system responding to a pregnancy. Thus, Study 2 provides support for the idea that a maternal immune response (and one that appears to be distinct from the maternal immune response hypothesized to explain the traditional fraternal birth order effect) is implicated in sexual orientation development. In Study 3, lesbian and heterosexual women differed in 17 facial features (out of 63) at the univariate level, and four were unique multivariate predictors. Gay and heterosexual men differed in 11 facial features at the univariate level, and three were unique multivariate predictors. Some of the facial features related to sexual orientation implicated a sexual differentiation related mechanism (e.g., prenatal hormones), whereas others implicated a non-sexual differentiation mechanism (e.g., developmental instability) to explain the sexual orientation-facial structure association. In addition to extending the empirical literature on the physical correlates associated with sexual orientation, the studies included in this dissertation extend our understanding of the various mechanisms likely implicated in the development of sexual orientation.
    • When and why is religious attendance associated with anti-gay bias? A justification-suppression model approach

      Hoffarth, Mark; Department of Psychology
      Even in relatively tolerant countries, anti-gay bias remains socially divisive, despite being widely viewed as violating social norms of tolerance. From a Justification-Suppression Model (JSM) framework, social norms may generally suppress anti-gay bias in tolerant countries, yet bias may be “released” by religious justifications among those who resist gay rights progress. I hypothesized that more frequent religious attendance would be associated with greater anti-gay bias, that this relation would be stronger in countries where anti-gay bias more strongly violates social norms of tolerance, and that the relation between religious attendance and anti-gay bias would be partially accounted for by religious justifications. In Part 1, I examined the relation between religious attendance and anti-gay bias in the US. In Part 2, I examined the relation between religious attendance and anti-gay bias across different countries. Finally, in Part 3, I examined religious justifications for anti-gay bias. Across large, nationally representative US samples and international samples (representing a total of 97 different countries), over 215,000 participants, and various indicators of anti-gay bias (e.g., dislike, moral condemnation, opposing gay rights), more frequent religious attendance was uniquely associated with greater anti-gay bias, over and above religious fundamentalism, political ideology, religious denomination, and other theoretically relevant covariates. Moreover, in 4 of 6 multilevel models, religious attendance was associated with anti-gay bias in countries with greater gay rights recognition, but was unrelated to anti-gay bias in countries with lower gay rights recognition. Google searches for a religious justification (“love the sinner hate the sin”) coincided temporally with gay-rights relevant searches. In U.S. and Canadian samples, much of the association between religious attendance and anti-gay bias was explained by “sinner-sin” religious justification, with religious attendance not associated with anti-gay bias when respondents reported relatively low familiarity with this justification. These findings suggest that social divisions on homosexuality in relatively tolerant social contexts may be in large part due to religious justifications for anti-gay bias (consistent with the JSM). Potential interventions building on these findings may include encouraging religious leaders to promote norms of tolerance and acceptance, increasing intergroup contact between frequent religious attenders and gays, and perspective-taking exercises.