Prenatal depression effects on early development: A review

This review of recent research on prenatal depression suggests that it is a strong predictor of postpartum depression and is more common than postpartum depression. Prenatal depression has been associated with excessive activity and growth delays in the fetus as well as prematurity, low birthweight, disorganized sleep and less responsiveness to stimulation in the neonate. Infants of depressed mothers have difficult temperament, and later in development attentional, emotional and behavioral problems have been noted during childhood and adolescence, as well as chronic illnesses in adulthood. Several variables have confounded the effects of prenatal depression including comorbid anxiety and anger as well as stressful life events. Potential mediating variables are low prenatal maternal dopamine and serotonin levels and elevated cortisol and norepinephrine. The associated intrauterine artery resistance may limit blood flow, oxygen and nutrients to the fetus. Some studies also suggest the heritability of developmental problems for the children of prenatally depressed mothers, including ADHD and antisocial behavior. Multivariate, longitudinal research is needed to disentangle these confounding and mediating variables.     

Individual differences in 2D:4D digit-ratios and otoacoustic emissions: Do they share a common developmental origin?

Differences across individuals in both 2D:4D, the ratio of the lengths of the 2nd-4th digit, and in otoacoustic emissions (OAEs), have been hypothesized to arise from differences in androgen exposure prenatally. Contrary to this hypothesis, however, McFadden and Shubel (2003) found no significant correlation between digit-ratios and OAE production. To further investigate the hypothesis of a common developmental origin, the current study assessed correlations between individual differences in 2D:4D and OAEs in 131 normally-hearing adults. All possible ratios of the 2nd, 3rd, 4th, and 5th digits were computed and OAEs, both spontaneously produced and in response to audible clicks, were measured. Observed correlations between digit length ratios and OAEs were largely nonsignificant. No significant correlations were found between 2D:4D and any of the five OAE measures. Fundamental differences in developmental timing and duration, postnatal influences, or factors other than prenatal androgens may explain the lack of associations.     

Lack of correlation between digit ratio (2D:4D) and Baron-Cohen’s “Reading the Mind in the Eyes” test, empathy, systemising, and autism-spectrum quotients in a general population sample

The second-to-fourth digit ratio (2D:4D) is sexually differentiated and is a likely biomarker for the organisational (permanent) effects of prenatal testosterone on the human brain. Recent research has highlighted a possible role of prenatal testosterone levels in both the etiology of autism-spectrum disorders and in sex and individual differences in cognitive styles of the normal mind (Baron-Cohen’s Extreme Male Brain Theory of Autism and Empathising/Systemising Theory). Importantly, autistic children present lower (hypermasculinised) 2D:4D than healthy controls. Based on these accounts, we investigated the relation of 2D:4D with Baron-Cohen’s measures of empathising (“Reading the Mind in the Eyes” test, RMET; Empathy Quotient, EQ), systemising (Systemising Quotient, SQ), and autistic-like traits (Autism-Spectrum Quotient, AQ) in the general population (N = 423 Austrian adults). Whereas sex differences into the expected direction and of expected size were obtained for all variables and internal scale consistencies tallied to retrievable reference values, 2D:4D was unrelated to RMET, EQ, SQ, and AQ scores. Candidate explanations for this lack of correlation might be possible developmental timing differences in the expression of 2D:4D and empathising/systemising, qualitative (as opposed to quantitative) functional differences between the normal and the autistic mind, or the suboptimal psychometric properties of the measures.     

Hormonal changes after competition predict sex‐differentiated decision‐making

Recent neuroendocrinology research has pointed out that testosterone (T) and cortisol (C) changes after social interactions can predict risk‐taking behavior in decision‐making, depending on the sex of participants. However, previous research has focused on the effects of the changes in only one hormone, rather than the interaction between them, even though C can suppress T activity. Our aim was to test, in men and women, the role of T changes moderated by C changes after competition in decision‐making. Thus, 48 males and 46 females completed the Iowa Gambling Task (IGT) after a laboratory competition or a noncompetitive task (control task). Saliva samples were collected before and after the competition/control task. IGT was employed to measure risk‐taking decision‐making, considering the degree of uncertainty. Our results showed sex‐differentiated effects of T and C changes on risk‐taking behavior. On the one hand, men from both task groups (Competition/Control) who had higher C and T changes after competition showed more risk‐taking decision‐making (higher IG Risk). On the other hand, women from the competitive task who had high C and T showed conservative decision‐making. Therefore, these results show sex‐differentiated decision‐making profiles, which would help to understand how men and women behave after experiencing a competitive social context.     

Gonadal hormones and intrasexual aggressive behavior in female bank voles (Clethrionomys glareolus)

The effects of gonadal hormones on aggressive behavior in the female bank vole was investigated in 10 min home cage tests. Ovariectomized (ovx) or intact females injected with oil, with progesterone (P), with a mixture of progesterone and estrogen (P+E), or with testosterone (T) alone were confronted in a resident-intruder test with unfamiliar, nonoperated females as intruders. Intact females showed aggressive behavior more frequently than ovx females. Ovx females injected with P, with P+E, or with T made significantly more attacks, and these attacks lasted longer than those observed for oil-treated voles. The results indicate that P, the typical female hormone, is responsible for aggressive behavior in female bank voles; however, only T increased the duration of interfemale aggression. Aggr. Behav. 24:63–70, 1998. © 1998 Wiley-Liss, Inc.     

Agonistic behavior,plasma testosterone,and hypothalamic estradiol binding in male rabbits

The purpose of this study was to establish a relation between agonistic behavior, gonadal hormones, and their receptorial capacity at the central level. Male rabbits were observed in seminatural conditions and three components of their agonistic behavior were recorded: follow, attack, and chase. The three behaviors were mutually correlated and clearly differed among the four members of each group. Within the social group, one rabbit was agonistically more active than the others and his supremacy was associated with an increased level of peripheral testosterone and higher estradiol binding in the hypothalamus. On the whole, the values of the hypothalamic estradiol binding were positively correlated with the behaviors. The results show that, in the male rabbit, agonistic activity is associated with changes in testosterone concentration and in the binding at the central level of its aromatized metabolite estradiol. Aggr. Behav. 23:33–40, 1997. © 1997 Wiley-Liss, Inc.     

Aggression and testosterone: Testing a bio-social model

Based upon reports of a positive correlation between circulating testosterone levels and aggression, we draw upon evolutionary psychology to place the action of testosterone in a broader perspective. We propose that testosterone affects competitive status-seeking and that under certain circumstances (including youth) this is expressed as aggression. Involvement in aggression in turn is associated with adherence to an instrumental social representation of aggression which justifies aggression as a means of imposing control over others and increasing self-esteem. Measures of salivary testosterone, masculinity, preferred social representation of aggression, and multiple aggression scales were collected from an undergraduate sample of 119 men. An Aggression factor was derived from principle components analysis of the aggression measures. The strongest correlates of Aggression were holding an instrumental social representation of aggression and youth. Testosterone showed no significant relationship to the single or aggregate measures of aggression or to any of the other psychometric measures. We suggest ways in which previous work may have over-estimated the strength of the association between circulating testosterone and aggression and discuss the possible relationships between age, social representation, and aggression. Aggr. Behav. 23:239–238, 1997. © 1997 Wiley-Liss, Inc.     

Awareness and Attitudes Regarding Prenatal Testing among Texas Women of Childbearing Age

Despite increased visibility and availability of prenatal testing procedures, very little is known about the attitudes among the populace toward these procedures. Using a computer assisted telephone interview of pregnant and non-pregnant women of childbearing age we analyze awareness and attitudes regarding prenatal tests among a diverse group of women of childbearing age in Texas. We also examine maternal characteristics associated with awareness and the willingness to undergo these procedures. While 89% were aware that such tests are available, younger, black and less educated women were less likely to know about prenatal tests for birth defects. Seventy-two percent of respondents said they would want their baby tested while Hispanic and black women were significantly more likely to express an interest than non-Hispanic whites. This study demonstrates the variability of knowledge and beliefs and confirms the importance of taking time to understand an individual’s personal beliefs, knowledge and attitudes about prenatal diagnosis.     

Serum cortisol,testosterone, and testosterone-binding globulin responses to competitive fighting in human males

Levels of circulating cortisol, testosterone, and testosterone-binding globulin were measured in 15 male wrestlers in relation to wrestling bouts and their outcomes. Concentrations of cortisol and testosterone increased consistently during wrestling bouts, while levels of testosterone-binding globulin dropped. Winners of competive matches showed greater increases in both cortisol and testosterone than losers. These findings indicate that humans, like other social mammals, may undergo specific endocrine changes in response to victory or defeat.