Mark R. Hoffarth

Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y

Significance Gay men have, on average, a greater number of older brothers than do heterosexual men, a well-known finding within sexual science. This finding has been termed the fraternal birth order effect. Strong scientific interest in sexual orientation exists because it is a fundamental human characteristic, and because its origins are often the focal point of considerable social controversy. Our study is a major advance in understanding the origins of sexual orientation in men by providing support for a theorized but previously unexamined biological mechanism—a maternal immune response to a protein important in male fetal brain development—and by beginning to explain one of the most reliable correlates of male homosexuality: older brothers. We conducted a direct test of an immunological explanation of the finding that gay men have a greater number of older brothers than do heterosexual men. This explanation posits that some mothers develop antibodies against a Y-linked protein important in male brain development, and that this effect becomes increasingly likely with each male gestation, altering brain structures underlying sexual orientation in their later-born sons. Immune assays targeting two Y-linked proteins important in brain development—protocadherin 11 Y-linked (PCDH11Y) and neuroligin 4 Y-linked (NLGN4Y; isoforms 1 and 2)—were developed. Plasma from mothers of sons, about half of whom had a gay son, along with additional controls (women with no sons, men) was analyzed for male protein-specific antibodies. Results indicated women had significantly higher anti-NLGN4Y levels than men. In addition, after statistically controlling for number of pregnancies, mothers of gay sons, particularly those with older brothers, had significantly higher anti-NLGN4Y levels than did the control samples of women, including mothers of heterosexual sons. The results suggest an association between a maternal immune response to NLGN4Y and subsequent sexual orientation in male offspring.

When Ideology Contradicts Self-Interest: Conservative Opposition to Same-Sex Marriage Among Sexual Minorities—A Commentary on Pinsof and Haselton (2016):

In a clever move to explain the political divide over same-sex marriage, Pinsof and Haselton (2016) demonstrated that adopting a short-term mating strategy and endorsing stereotypes of sexual minorities as promiscuous (and therefore threatening to monogamous lifestyles) work in tandem to produce opposition to same-sex marriage. Although Pinsof and Haselton did not demonstrate that mating strategies and stereotype endorsement statistically mediate (or explain) the tendency for conservatives to oppose same-sex marriage more than liberals, they included political orientation as a covariate and suggested that conservatives are more likely than liberals to pursue short-term mating strategies and to endorse stereotypes of gay people as promiscuous. Pinsof and Haselton couched their findings in terms of Weeden and Kurzban’s (2014) evolutionarypsychology approach, which emphasizes the role of selfinterest in political ideology. Thus, they argued that heterosexuals who are eager to marry and start families early on would be threatened by the lifestyles they believe sexual minorities lead. Although it is not entirely clear why, from the standpoint of self-interest, heterosexuals’ relationships would be jeopardized by the choices made by same-sex couples (assuming that, in general, they are trading in different sexual marketplaces), this perspective has led to some interesting empirical observations. An important issue that was neglected by Pinsof and Haselton pertains to the political divide within the group of sexual minorities. Although most sexual minorities support same-sex marriage at this point, it is reasonable to expect variability in opinion. Previous research on aspects of system-justification theory has revealed that gays and lesbians who are relatively more conservative—much like heterosexuals who are conservative—hold less favorable attitudes about sexual minorities (Jost, Banaji, & Nosek, 2004) and are less enthusiastic about their participation in family life (Pacilli, Taurino, Jost, & van der Toorn, 2011). This finding is consistent with the notion that conservative attitudes reflect a defensive motivation to justify the societal status quo ( Jost, Glaser, Kruglanski, & Sulloway, 2003); therefore, conservative attitudes may be congruent with self-interest for people who are advantaged by the status quo but incongruent with self-interest for those who are disadvantaged by it (Jost, Burgess, & Mosso, 2001). Because conservative sexual minorities (compared with liberal sexual minorities) exhibit greater out-group favoritism, sexual self-stigmatization, and opposition to same-sex parenting (e.g., Jost et al., 2004; Pacilli et al., 2011), we hypothesized that sexual minorities who are more conservative are more likely to stereotype sexual minorities as promiscuous and to oppose same-sex marriage. In this case, conservative ideology would have precisely the same attitudinal consequences as it does for heterosexual people, but it would conflict with objective self-interest, given that individuals with samesex attractions would be deprived of legal acceptance of these relationships. Pinsof and Haselton reported results from their full sample, which included 8.4% sexual minorities, and noted that their results were the same when sexual minorities were excluded. They did not discuss results 694866 PSSXXX10.1177/0956797617694866Hoffarth, JostWhen Ideology Contradicts Self-Interest research-article2017

Of filthy pigs and subhuman mongrels: Dehumanization, disgust, and intergroup prejudice

Representing others as less-than-human can have profound consequences, delegitimizing the target and removing them from protections otherwise afforded to “people.” This review explores recent developments in research on both outgroup dehumanization and the emotion of (intergroup) disgust, factors increasingly receiving attention for their importance in explaining intergroup relations. We specifically explore topics such as the human-animal divide (i.e., the sense that humans are different from and superior to non-human animals) and intergroup disgust sensitivity (i.e., revulsion reactions toward outgroups, particularly those foreign in nature). We conclude that: a) human outgroup prejudices (e.g., racism) find their origins, in part, in human-animal relations; b) our expressed revulsion toward other groups plays a meaningful role in explaining bias, beyond ideology and related emotions (e.g., intergroup anxiety); c) the field needs to integrate dehumanization and disgust into existing theories of intergroup prejudice to better understand the ways we psychologically distance ourselves from outgroups.

Development and validation of the Attitudes Towards Asexuals (ATA) scale

Although asexuality (i.e., lack of sexual attraction) is receiving increasing public and academic attention, anti-asexual bias has been the focus of little empirical study. Here, we develop a measure of anti-asexual bias, the Attitudes Towards Asexuals (ATA) scale, consisting of a 16-item factor with strong reliability (α = .94). The ATA demonstrated convergent validity in terms of correlations with individual differences (e.g., positive relations with Right-Wing Authoritarianism, Social Dominance Orientation) and anti-asexual behavioural intentions (e.g., discomfort renting to and hiring asexuals, contact avoidance). Further, these relations were statistically unique from singlism (i.e., bias against singles). In addition, we found relations between greater ATA and greater sexism, greater traditional gender norm endorsement and lower past intergroup contact with asexuals, suggesting potential avenues for expanding our understanding of anti-asexual bias. Implications for examining anti-asexual bias as a distinct form of sexual prejudice are discussed.

When and Why Is Religious Attendance Associated With Antigay Bias and Gay Rights Opposition? A Justification-Suppression Model Approach.

Even in relatively tolerant countries, antigay 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 antigay bias in tolerant countries, yet be “released” by religious justifications among those who resist gay rights progress. Across large, nationally representative US samples (Study 1) and international samples (Study 2, representing a total of 97 different countries), over 215,000 participants, and various indicators of antigay bias (e.g., dislike, moral condemnation, opposing gay rights), individual differences in religious attendance was uniquely associated with greater antigay bias, over and above religious fundamentalism, political ideology, and religious denomination. Moreover, in 4 of 6 multilevel models, religious attendance was associated with antigay bias in countries with greater gay rights recognition, but was unrelated to antigay bias in countries with lower gay rights recognition (Study 2). In Study 3, Google searches for a religious justification (“love the sinner hate the sin”) coincided temporally with gay-rights relevant searches. In U.S. (Study 4) and Canadian (Study 5) samples, much of the association between religious attendance and antigay bias was explained by “sinner–sin” religious justification, with religious attendance not associated with antigay bias when respondents reported relatively low familiarity with this justification (Study 5). These findings suggest that social divisions on homosexuality in relatively tolerant social contexts may be in large part due to religious justifications for antigay bias (consistent with the JSM), with important implications for decreasing bias.