Prenatal Hormonal Contributions to Sex Differences in Human Cognitive and Personality Development. In: Gerall AA, Moltz H, Ward IL, editors. Sexual Differentiation. Boston: Springer US; 1992. pp. 221-43. [DOI: 10.1007/978-1-4899-2453-7_7]

Dyadic parent-infant interaction patterns at 12 months: Exploring dyadic parent-infant gender compositions

This study investigates differences in dyadic mother-infant and father-infant interaction patterns at infant age 12 months, and the relation between different parent-infant gender compositions and the dyadic interaction. Data were drawn from a large-scale, population-based Norwegian community sample comprising 671 mother-infant and 337 father-infant interactions. The Early Relational Health Screen (ERHS), a screening method for observing dyadic parent-infant interactions, was used to assess the parent-infant interactions. Scores on the ERHS were employed to investigate dyadic differences in the overall interaction scores, and dyadic interaction on seven sub-dimensions between mother-infant and father-infant pairs. The relation between different parent-infant gender compositions and the dyadic interaction scores was also examined. As expected in a normative sample, most parent-infant interactions received scores in the upper rating levels. Differences between mother-infant and father-infant patterns were generally small, but mother-infant dyads tended to obtain slightly higher scores. The mother-infant dyads received higher scores on the dimensions of engagement and enjoyment, but no other significant differences between the parent-infant pairs were found for the remaining dimensions. We did not find evidence for a moderation effect of child gender. However, parent-daughter dyads received somewhat higher scores than the parent-son dyads.

Sexual Orientation in Individuals With Congenital Adrenal Hyperplasia: A Systematic Review

Congenital adrenal hyperplasia (CAH) is a genetic condition of the steroidogenic enzymes in the adrenal cortex normally leading to variable degrees of cortisol and aldosterone deficiency as well as androgen excess. Exposure to androgens prenatally might lead to ambiguous genitalia. The fetal brain develops in traditional male direction through a direct action of androgens on the developing nerve cells, or in the traditional female direction in the absence of androgens. This may indicate that sexual development, including sexual orientation, are programmed into our brain structures prenatally. The objective of this study was to perform a systematic review of the literature, investigating sexual orientation in individuals with CAH. The study also aimed at identifying which measures are used to define sexual orientation across studies. The review is based on articles identified through a comprehensive search of the OVIDMedline, PsycINFO, CINAHL, and Web of Science databases published up to May 2019. All peer-reviewed articles investigating sexual orientation in people with CAH were included. Quantitative, qualitative, and mixed methods were considered, as well as self-, parent-, and third-party reports, and no age or language restrictions were enforced on publications. The present review included 30 studies investigating sexual orientation in patients with CAH assigned female at birth (46, XX) (n = 927) or assigned male at birth (46, XY and 46, XX) (n = 274). Results indicate that assigned females at birth (46, XX) with CAH had a greater likelihood to not have an exclusively heterosexual orientation than females from the general population, whereas no assigned males at birth (46, XY or 46, XX) with CAH identified themselves as non-heterosexual. There was a wide diversity in measures used and a preference for unvalidated and self-constructed interviews. Hence, the results need to be interpreted with caution. Methodological weaknesses might have led to non-heterosexual orientation being overestimated or underestimated. The methodological challenges identified by this review should be further investigated in future studies.

Scrutinizing Immutability: Research on Sexual Orientation and U.S. Legal Advocacy for Sexual Minorities

We review scientific research and legal authorities to argue that the immutability of sexual orientation should no longer be invoked as a foundation for the rights of individuals with same-sex attractions and relationships (i.e., sexual minorities). On the basis of scientific research as well as U.S. legal rulings regarding lesbian, gay, and bisexual (LGB) rights, we make three claims: First, arguments based on the immutability of sexual orientation are unscientific, given what we now know from longitudinal, population-based studies of naturally occurring changes in the same-sex attractions of some individuals over time. Second, arguments based on the immutability of sexual orientation are unnecessary, in light of U.S. legal decisions in which courts have used grounds other than immutability to protect the rights of sexual minorities. Third, arguments about the immutability of sexual orientation are unjust, because they imply that same-sex attractions are inferior to other-sex attractions, and because they privilege sexual minorities who experience their sexuality as fixed over those who experience their sexuality as fluid. We conclude that the legal rights of individuals with same-sex attractions and relationships should not be framed as if they depend on a certain pattern of scientific findings regarding sexual orientation.

Effects of gender on the health and development of medically at-risk infants

OBJECTIVES

To examine gender-differentiated health and cognitive/motor/language developmental outcomes among medically at-risk infants.

DESIGN

Longitudinal descriptive and comparative secondary analysis.

SETTING

Neonatal Intensive Care Unit, intermediate care unit, and infectious disease clinic of tertiary medical centers in the southeast and east United States.

PARTICIPANTS

One hundred eight (108) premature infants, 67 medically fragile infants, and 83 infants seropositive for HIV.

METHODS

Neonatal and later health variables were obtained from the medical record to determine the technology dependence scores and frequency of common health problems. Data for physical growth and cognitive/motor/language development were obtained through the physical measurement, including the Bayley Scales of Infant Development-Second Edition, the Vineland Adaptive Behavior Scale, the Toll Control Developmental Checklist, and the Preschool Language Scale-3 during home visits between 6 and 27 months corrected ages.

RESULTS

Fewer effects on health and developmental outcomes related to gender were observed with medically fragile infants than the other two groups of infants. The cognitive/motor/language scores were decreased with increasing age of the infants in all groups.

CONCLUSION

Male gender can be considered a significant biological risk factor for infants' cognitive and motor development, especially for premature infants. Because of their increased risk, it is recommended that male infants who are born prematurely or seropositive for HIV have early and advanced developmental screening tests by trained personnel through periodic pediatric clinic.

Gender differences in relations of mental rotation, verbal fluency, and SAT scores to finger length ratios as hormonal indexes

One hundred thirty-four university students (93 women, 41 men) were administered the Vandenberg Mental Rotation Test and the Thurstone Word Fluency Test, and they were asked to report their Scholastic Achievement Test scores. Finger lengths were measured, because literature has reported gender differences in the ratio of the 2nd to 4th, 2nd to 3rd, and 2nd to 5th finger lengths, such that the ratio is larger in women than in men. The goal of this study was to evaluate the relations between finger-length ratios and cognitive skills, such as spatial skills and verbal fluency, which have shown gender differences and direct relations to hormonal effects. Gender differences were found in the expected directions, such that the men performed better than the women for mental rotation, the women performed better than the men for verbal fluency, and the finger-length ratios were in the directions reported in the literature. The finger-length ratios showed an interesting relation with the cognitive variables for the men and women. For the men, better performance on the measures, including mental rotation, verbal fluency, and verbal Scholastic Achievement Test score was associated with less of a male-typical finger-length ratio pattern, or higher ratios. For the women, better performance for mental rotation and verbal fluency was associated with less of a female-typical finger-length ratio pattern, or lower ratios. Thus, in this group of college students, better cognitive performance was associated with a less gender-typical finger-length ratio, for both men and women. These findings are discussed in the context of other similar reports and a possible curvilinear relation between hormones and cognition in normal populations.

Relation between language lateralisation and spatial ability in gay and straight women and men

Delineating the relationship between language lateralisation and spatial ability remains an elusive goal. To explore the association of sexual orientation to the language lateralisation/spatial ability relationship, heterosexual (HT) women, HT men, lesbians, and gay men (20 per group) completed a divided-visual-field lexical-decision task to assess relative degrees of language lateralisation, as well as a Water Level Task (WLT) and two Mental Rotation (MR) Tasks designed to assess spatial ability. A significant cross-sex shift was revealed in the language lateralisation of gay men. Further, language lateralisation positively correlated with MR ability in HT men and tended to positively correlate with spatial perception in HT women. No significant associations were revealed in homosexual subjects. Different patterns of functional hemispheric asymmetry in homosexual and heterosexual individuals are discussed in relation to early neurobiological factors influencing the development of sexual orientation.

Cognitive efficiency on a match to sample task decreases at the onset of puberty in children

Electrocortical evidence indicates that a wave of synaptic proliferation occurs in the frontal lobes around the age of puberty onset. To study its potential influence on cognition, we examined 246 children (10-17 years) and 49 young adults (18-22 years) using a match-to-sample type of task to measure reaction times to assess emotionally related information. Based upon the instruction set, subjects made a yes/no decision about the emotion expressed in a face, a word, or a face/word combination presented tachistoscopically for 100 ms. The faces were images of a single individual with a happy, angry, sad or neutral expression. The words were 'happy,' 'angry,' 'sad,' or 'neutral,' In the combined stimulus condition, subjects were asked to decide if the face and word matched for the same emotion. Results showed that compared to the previous year, reaction times were significantly slower for making a correct decision at 11 and 12 years of age in girls and boys, the approximate ages of puberty onset. The peripubertal rise in reaction time declined slowly over the following 2-3 years and stabilized by 15 years of age. Analyses of the performance of 15-17 year olds revealed significantly longer reaction times in females to process both faces and words compared to males. However, this sex difference in late puberty appeared to be transient since it was not present in 18-22 year olds. Given the match-to-sample nature of the task employed, the puberty related increases in reaction time may reflect a relative inefficiency in frontal circuitry prior to the pruning of excess synaptic contacts.

Stereotypes and steroids: using a psychobiosocial model to understand cognitive sex differences

To further our understanding of cognitive sex differences, we studied the relationship between menstrual phase (via serum estradiol and progesterone levels) and cognitive abilities and cognitive performance in a sample of medical students in eastern Turkey. As expected, we found no sex differences on the Cattell "Culture Fair Intelligence Test" (a figural reasoning test), with females scoring significantly higher on a Turkish version of the Finding A's Test (rapid word knowledge) and males scoring significantly higher on a paper-and-pencil mental rotation test. The women showed a slight enhancement on the Finding A's Test and a slight decrement in Cattell scores during the preovulatory phase of their cycle that (probably) coincided with a rise in estrogen. There were also small cycle-related enhancements in performance for these women on the mental rotation test that may reflect cyclical increases in estrogen and progesterone. Additional analyses showed an inverted U-shaped function in level of estradiol and the Cattell Test. Finally, for women who were tested on Day 10 of their menstrual cycle, there was a negative linear relationship between their Cattell scores and level of progesterone. Stereotypes about the cognitive abilities of males and females did not correspond to performance on the mental rotation or Finding A's Test, so the sex-typical results could not be attributed to either stereotype threat or stereotype activation. For practical purposes, hormone-related effects were generally small. Variations over the menstrual cycle do not provide evidence for a "smarter" sex, but they do further our understanding of steroidal action on human cognitive performance.

Hormonal contributions to sexually dimorphic behavioral development in humans

Nineteen studies on the behavioral effects of prenatal exposure to hormones administered for the treatment of at-risk human pregnancy are reviewed. Because the role of prenatal exposure to hormones in the development of human behavioral sex differences is potentially confounded by society's differential treatment of the sexes, comparisons between exposed and unexposed subjects were evaluated and summarized separately for male and female subjects. Therefore, this review focuses on data for individuals whose prenatal hormone environments were atypical relative to what is normal for their own sex. Overall, it appears that prenatal exposure to androgen-based synthetic progestin exerted a masculinizing and/or defeminizing influence on human behavioral development, whereas prenatal exposure to natural progesterone and progesterone-based synthetic progestin had a feminizing and/or demasculinizing influence, particularly among female subjects. The data on prenatal exposure to synthetic estrogen derive primarily from subjects exposed to diethylstibestrol (DES). DES-exposed male subjects appeared to be feminized and/or demasculinized, and there is some evidence that exposed female subjects were masculinized. These findings are discussed in the context of prenatal hormonal contributions to sexually dimorphic behavioral development both within and between the sexes. Recommendations for the conduct of future research in developmental behavioral endocrinology are presented.