Extreme right-handedness, older brothers, and sexual orientation in men.

Two of the most consistent correlates of sexual orientation in men are handedness and fraternal birth order (i.e., number of older brothers). In the present study, the relationship among handedness, older brothers, and sexual orientation was studied in 4 samples of heterosexual and gay or bisexual men (N = 944). Unlike previous studies, which have only observed an increased rate of non-right-handedness in gay or bisexual men relative to heterosexual men, an elevated rate of extreme right-handedness was found in gay or bisexual men relative to heterosexual men. The results also demonstrated that older brothers moderate the relationship between handedness and sexual orientation. Specifically, older brothers increase the odds of being gay or bisexual in moderate right-handers only; in both non-right-handers and extreme right-handers, older brothers do not affect (or decrease) the odds of being gay or bisexual. The results have implications for an early neurodevelopmental origin to sexual orientation in men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of birth order, handedness, and sexual orientation in the Kinsey interview data.

Recent evidence indicates that 2 of the most consistently observed correlates of men's sexual orientation--handedness and older brothers--may be linked interactively in their prediction of men's sexual orientation. In this article, the authors studied the relationship among handedness, older brothers, and men's sexual orientation in the large and historically significant database originally compiled by Alfred C. Kinsey and his colleagues (A. C. Kinsey, W. B. Pomeroy, & C. E. Martin, 1948). The results demonstrated that handedness moderates the relationship between older brothers and sexual orientation. Specifically, older brothers increased the odds of homosexuality in right-handers only; in non-righthanders, older brothers did not affect the odds of homosexuality. These results refine the possible biological explanations reported to underlie both the handedness and older brother relationships to men's sexual orientation. These results also suggest that biological explanations of men's sexual orientation are likely relevant across time, as the Kinsey data comprise an older cohort relative to modern samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the association between sexual attraction and adolescent risk behavior involvement: Examining mediation and moderation.

On the basis of a large-scale survey of high-school youth, the authors compared adolescents reporting exclusively heterosexual, mostly heterosexual, bisexual, and predominately same-sex attraction based on high-risk involvement across a range of risk behaviors. Bisexual and same-sex attracted groups were characterized by heightened high-risk involvement relative to the other two groups. Mediation analysis was used to determine whether these group disparities were explained by a set of normative predictive factors spanning multiple life domains. Differences among a combined exclusively/mostly heterosexual attraction group and both the bisexual and same-sex attraction groups were attenuated (66% and 50%, respectively) after incorporating the hypothesized intervening predictive factors, providing evidence of partial mediation. Primary mediators included intrapersonal (attitudes toward risk-taking; academic orientation), interpersonal (peer victimization; parental relationships; unstructured activities), and environmental (substance availability) factors. Mediation results were consistent across participant age and sex. Implications, limitations, and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interaction of fraternal birth order and body size in male sexual orientation.

A late fraternal birth order has been demonstrated numerous times in homosexual men. Body size has been less studied with regard to the development of sexual orientation and has demonstrated contradictory results. In this research, the relations among fraternal birth order, body size, and sexual orientation were examined in a Canadian sample of homosexual and heterosexual men. An interaction between fraternal birth order and height was observed, with a homosexual orientation most likely to occur in men with a high number of older brothers and shorter stature. No significant interactive effects were observed for weight. The results suggest that the mechanism underlying the fraternal birth order phenomenon has an effect on physical development that lasts and is detectable into adulthood (i.e., adult stature). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hair whorl direction and sexual orientation in human males.

Hair whorl direction is a somatic feature that is organized early during neurodevelopment and unlikely to be influenced by social factors. This study aimed to replicate a widely reported association by A. J. S. Klar (2003) between counterclockwise hair whorl direction and homosexuality in men, using more objective methodology. The authors took digital photographs of parietal surface hair whorls from 100 heterosexual men and 100 homosexual men who were predominantly right-handed. These images were rated for clockwise and counterclockwise direction (for which no more than 1 hair whorl was present) by 2 raters unaware of sexual orientation. The authors found no significant difference between heterosexual and homosexual men in hair whorl direction, but the authors did replicate the fraternal birth order effect (more older brothers for homosexual men). Number of older sisters was positively correlated with counterclockwise hair whorls in heterosexual men. These data were discussed in relation to prenatal factors assumed to play a role in the neurodevelopment of male homosexuality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An inclusive response to LGB and conservative religious persons: The case of same-sex attraction and behavior.

How should psychologists demonstrate respect for religion as an aspect of diversity when that aspect of diversity seems inconsistent with another form of diversity? This is a striking challenge when considering conservative expressions of religion in relation to a person's experience of same-sex attraction and behavior. This article (a) asserts that conservative religion is a legitimate, though often overlooked, expression of diversity; (b) identifies ways in which gay-integrative theorists and conservative religious persons fail to appreciate each other's perspective; and (c) presents a continuum of service delivery options to expand clinical services to persons who experience same-sex attraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual orientation and suicide attempt: A longitudinal study of the general Norwegian adolescent population.

Past and future suicide attempt rates among gay, lesbian, and bisexual (GLB) young people were compared with those of heterosexual young people. A sample of Norwegian students (N=2,924; grades 7-12) was followed in 3 data collection waves. Risk factors included previous suicide attempt, depressed mood, eating problems, conduct problems, early sexual debut, number of sexual partners, pubertal timing, self-concept, alcohol and drug use, atypical gender roles, loneliness, peer relations, social support. parental attachment, parental monitoring, and suicidal behavior among family and friends. When homosexual attraction, homosexual identity, and same-sex sexual behavior were entered to predict suicide attempt, only same-sex sexual behavior was significantly predictive. The increased odds could not be attributed to GLB students' greater exposure to risk factors for suicide attempt. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Minority stress and mental health among Dutch LGBs: Examination of differences between sex and sexual orientation.

Minority stress is often cited as an explanation for greater mental health problems among lesbian, gay, and bisexual (LGB) individuals than heterosexual individuals. However, studies focusing on sex or sexual orientation differences in level of minority stress and its impact on mental health are scarce, even more so outside the United States. Performing secondary analyses on the data of a Dutch population study on sexual health, the present study examines the robustness of the minority stress model by explaining mental health problems among men and women with mostly or only same-sex sexual attraction, and men and women who are equally attracted to same-sex and opposite-sex partners in the “gay-friendly” Netherlands (N = 389; 118 gay men, 40 bisexual men, 184 lesbian women, and 54 bisexual women). Results showed that minority stress is also related to mental health of Dutch LGBs. Participants with a higher level of internalized homonegativity and those who more often encountered negative reactions from other people on their same-sex sexual attraction reported more mental health problems. Such negative reactions from others, however, had a stronger link with mental health among lesbian/gay than among bisexual participants. Openness about one's sexual orientation was related to better mental health among sexual minority women, but not among their male counterparts. Suggestions for future research, implications for counseling, and other societal interventions are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

[Review of Sexual behavior in the human female; Sex ethics and the Kinsey reports; and Twenty-five years of sex research. History of the National Research Council Committee for Research in Problems of Sex, 1922-1947].

Reviews the books Sexual behavior in the human female by A. C. Kinsey et al. (see record 1954-05526-000); Sex ethics and the Kinsey reports by S. Hiltner (1953); and Twenty-five years of sex research. History of the National Research Council Committee for Research in Problems of Sex, 1922-1947 by Sophie D. Aberle, and G. W. Corner (see record 1954-02151-000). Concerning the first book, this review merely points to the facts that have been marshalled in the enormous range of individual differences in reported capacity, or rather claimed performance, and to the extensive detailed information set forth in Part III entitled "Comparisons of Female and Male." The sex difference shown by the fact that in 30 out of 33 items the male, on the average, is more readily affected by psychological stimuli is worthy of special note. This finding provides a wealth of insight for better understanding of the psychology of human males and females. Hiltner's work will aid many clergymen to assimilate the findings with a minimum of trauma. It should enable them to do a better job of understanding and counseling their parishoners, young or old. The significance of Kinsey's work and of Hiltner's interpretation can be fully understood only by studying the magnificent achievements of the NRC Committee for Research in Problems of Sex. Aberle and Corner's report gives due credit to Robert M. Yerkes who was chairman from 1922 to 1947. Yerkes' foresight, initiative, tact, courage, and everlasting persistence were primarily responsible for this development. The Committee courageously supported research on all aspects of sex in all species from paramecium to man. Thus psychology has moved from an intellectualistic preoccupation with man as a rational being to a more realistic understanding of man as a behaving organism in all of his manifold adjustments. In short, sex can no longer be ignored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Sexual Behavior in the Human Female.

Reviews the book, Sexual Behavior in the Human Female by A. C. Kinsey, W. B. Pomeroy, C. E. Martin, & P. H. Gebhard (see record 1954-05526-000). According to the reviewer, this volume is the second progress report made by Kinsey and his research staff based on their fact-finding investigation of human sex behavior. The purpose of the survey is described as "an attempt...to discover what people do sexually, what factors may account for their patterns of sexual behavior, how their sexual experiences have affected their lives, and what social significance there may be in each type of behavior." Most of the statistical data presented in the volume (179 tables and 155 figures) are based on the sex histories of 5,940 white females. In all, over 16,000 histories collected over a 15-year period by the staff of the Institute for Sex Research provide the basic research data on which this report is based. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of humidity on reproductive behavior in male and female zebra finches (Taeniopygia guttata).

Zebra finches (Taeniopygia guttata) are regarded as opportunistic breeders with reproductive behaviors mediated by short-term proximal environmental conditions. This article provides experimental evidence for the role of humidity in reproductive behaviors. Zebra finches were subjected to experimentally manipulated high levels of relative humidity. Males gathered more nest material and sang more. Females showed no relationship between humidity and gathering nest materials, egg laying, or changes in rates of vocalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy and awareness in the perception and categorization of male sexual orientation.

For clear and unambiguous social categories, person perception occurs quite accurately from minimal cues. This article addresses the perception of an ambiguous social category (male sexual orientation) from minimal cues. Across 5 studies, the authors examined individuals' actual and self-assessed accuracy when judging male sexual orientation from faces and facial features. Although participants were able to make accurate judgments from multiple facial features (i.e., hair, the eyes, and the mouth area), their perceived accuracy was calibrated with their actual accuracy only when making judgments based on hairstyle, a controllable feature. These findings provide evidence that suggests different processes for extracting social category information during perception: explicit judgments based on obvious cues (hairstyle) and intuitive judgments based on nonobvious cues (information from the eyes and mouth area). Differences in the accuracy of judgments based on targets' controllability and perceivers' awareness of cues provides insight into the processes underlying intuitive predictions and intuitive judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical access in younger and older adults: The case of the mass/count distinction.

Although lexicosemantic deficits are not typically seen in older adults, some studies indicate that age-related changes in semantic processing may occur. We had groups of older and younger adults perform speeded lexical decision on mass (e.g., honey), count (e.g., car), and dual nouns, which may be either mass or count (e.g., lamb). Singular dual nouns engendered significantly faster response times in older adults than mass and count nouns, whereas younger adults manifested similar response times to count and dual nouns. These results point toward a three-way distinction in the lexicon between mass, count, and dual nouns. Older adults appear to treat a larger set of nouns as dual than do younger adults. This may be due to awareness of the mass/count ambiguity present in a greater number of lexical items, as a result of their greater linguistic experience. Alternatively, in order to conserve processing resources, older adults may not activate mass/count information when recognizing a dual noun unless a mass or count reading is forced by context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accounting for changes in social support among married older adults: Insights from the MacArthur Studies of Successful Aging.

Using longitudinal, community-based data from the MacArthur Studies of Successful Aging, the authors examined determinants of changes in social support receipt among 439 married older adults. In general, social support increased over time, especially for those with many preexisting social ties, but those experiencing more psychological distress and cognitive dysfunction reported more negative encounters with others. Gender affected social support receipt: Men received emotional support primarily from their spouses, whereas women drew more heavily on their friends and relatives and children for emotional support. Discussion centers on the importance of social support provision to those with the greatest needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paternal care in the social and diurnal striped mouse (Rhabdomys pumilio): Laboratory and field evidence.

Paternal care is rare in mammals, occurring mainly in carnivores and neotropical primates, in which the difficulties of long generation time and large individuals lead to small sample sizes. Here, the authors show that paternal care can be easily studied in the four-striped mouse (Rhabdomys pumilio) because (a) captive males show all the patterns of parental care as do females, with the obvious exception of nursing; (b) in the field, wild males act amicably toward juveniles and retrieve pups experimentally presented to them; (c) the striped mouse facilitates experimental approaches in captivity because it has a short generation period and can be kept in large numbers; and (d) the striped mouse is diurnal, not only making observations in captivity easier but also enabling direct observations in the field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Main predictions of the interpersonal–psychological theory of suicidal behavior: Empirical tests in two samples of young adults.

The interpersonal–psychological theory of suicidal behavior (T. E. Joiner, 2005) makes 2 overarching predictions: (a) that perceptions of burdening others and of social alienation combine to instill the desire for death and (b) that individuals will not act on the desire for death unless they have developed the capability to do so. This capability develops through exposure and thus habituation to painful and/or fearsome experiences and is posited by the theory to be necessary for overcoming powerful self-preservation pressures. Two studies tested these predictions. In Study 1, the interaction of (low) family social support (cf. social alienation or low belonging) and feeling that one does not matter (cf. perceived burdensomeness) predicted current suicidal ideation, beyond depression indices. In Study 2, the 3-way interaction among a measure of low belonging, a measure of perceived burdensomeness, and lifetime number of suicide attempts (viewed as a strong predictor of the level of acquired capability for suicide) predicted current suicide attempt (vs. ideation) among a clinical sample of suicidal young adults, again beyond depression indices and other key covariates. Implications for the understanding, treatment, and prevention of suicidal behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A cross-cultural analysis of the behavior of women and men: Implications for the origins of sex differences.

This article evaluates theories of the origins of sex differences in human behavior. It reviews the cross-cultural evidence on the behavior of women and men in nonindustrial societies, especially the activities that contribute to the sex-typed division of labor and patriarchy. To explain the cross-cultural findings, the authors consider social constructionism, evolutionary psychology, and their own biosocial theory. Supporting the biosocial analysis, sex differences derive from the interaction between the physical specialization of the sexes, especially female reproductive capacity, and the economic and social structural aspects of societies. This biosocial approach treats the psychological attributes of women and men as emergent given the evolved characteristics of the sexes, their developmental experiences, and their situated activity in society. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual orientation and the second to fourth finger length ratio: A meta-analysis in men and women.

The ratio of the lengths of the second and fourth fingers (2D:4D) may serve as a marker for prenatal androgen signaling. Because people are typically unaware of their 2D:4D, its use allows possible effects of early sex hormone regimes and socialization to be disentangled. We conducted a meta-analysis on relationships between 2D:4D and sexual orientation in men and women in 18 independent samples of men and 16 independent samples of women. Collectively, these samples comprised 1,618 heterosexual men, 1,693 heterosexual women, 1,503 gay men, and 1,014 lesbians. In addition to identifying the normative heterosexual sex difference in 2D:4D for both hands, we found that heterosexual women had higher (more feminine) left- and right-hand 2D:4D than did lesbians, but we found no difference between heterosexual and gay men. Moderator analyses suggested that ethnicity explained some between-studies variation in men. These results add to a literature suggesting that early sex hormone signaling affects sexual orientation in women, and highlight the need for further research exploring the relationships among 2D:4D, sexual orientation, and ethnicity in men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in the use of demand and withdraw behavior in marriage: Examining the social structure hypothesis.

Studies consistently show sex differences in married couples' use of demand and withdraw behavior. The social structure hypothesis proposes that these differences are the result of power differentials between spouses. This study examined the link between 3 aspects of marital power and demanding and withdrawal behavior. Contrary to social structure predictions, results showed that wives did not possess less decision-making ability or access to resources and appeared to exhibit greater situational power (i.e., domineering and dominant behaviors) than did their husbands during problem-solving discussions. Furthermore, the spouse who exhibited the most demands also exhibited the most domineering and dominant behaviors, whereas the spouse who exhibited the most withdrawal exhibited the least domineering and dominant behaviors during problem-solving discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alcohol on tests of executive functioning in men and women: A dose response examination.

[Correction Notice: An erratum for this article was reported in Vol 19(4) of Experimental and Clinical Psychopharmacology (see record 2011-16762-001). This article contained errors in the text. These errors are explained and corrected in the correction.] Alcohol has been shown to affect performance on tasks associated with executive functioning. However, studies in this area have generally been limited to a single dose or gender or have used small sample sizes. The purpose of this study was to provide a more nuanced and systematic examination of alcohol's effects on commonly used tests of executive functioning at multiple dosages in both men and women. Research volunteers (91 women and 94 men) were randomly assigned to one of four drink conditions (alcohol doses associated with target blood alcohol concentrations of .000%, .050%, .075%, and .100%). Participants then completed three tasks comprising two domains of executive functioning: two set shifting tasks, the Trail Making Test and a computerized version of the Wisconsin Card Sorting Task, and a response inhibition task, the GoStop Impulsivity Paradigm. Impaired performance on set shifting tasks was found at the .100% and .075% dosages, but alcohol intoxication did not impair performance on the GoStop. No gender effects emerged. Thus, alcohol negatively affects set shifting at moderately high levels of intoxication in both men and women, likely attributable to alcohol's interference with prefrontal cortex function. Although it is well established that alcohol negatively affects response inhibition as measured by auditory stop-signal tasks, alcohol does not appear to exert a negative effect on response inhibition as measured by the GoStop, a visual stop-signal task. (PsycINFO Database Record (c) 2011 APA, all rights reserved)