Saturday, May 25, 2019

Preferences for beards when judging fathering potential were strongest among mothers; they prefered beards when judging fathering potential but not attractiveness, which may reflect selection for direct benefits

Mothers are sensitive to men's beards as a potential cue of paternal investment. Barnaby J. W. Dixson, Siobhan Kennedy-Costantini, Anthony J. Lee, Nicole L. Nelson. Hormones and Behavior, Volume 113, July 2019, Pages 55-66.

•    The first study to test if motherhood is associated with preferences for men's beards.
•    Preferences for beards when judging fathering potential were strongest among mothers.
•    Parous women prefered beards when judging fathering potential but not attractiveness.
•    Women's preferences for men's beards may reflect selection for direct benefits.

Abstract: Mating strategy theories assert that women's preferences for androgen dependent traits in men are stronger when the costs of reduced paternal investment are lowest. Past research has shown that preferences for facial masculinity are stronger among nulliparous and non-pregnant women than pregnant or parous women. In two studies, we examine patterns in women's preferences for men's facial hair – likely the most visually conspicuous and sexually dimorphic of men's secondary sexual traits – when evaluating men's masculinity, dominance, age, fathering, and attractiveness. Two studies were conducted among heterosexual pregnant women, mothers, non-contractive and contraceptive users. Study 1 used a between-subjects sample (N = 2103) and found that mothers had significantly higher preferences for beards when judging fathering than all other women. Pregnant women and mothers also judged beards as more masculine and older, but less attractive, than non-contractive and contraceptive users. Parous women judged beards higher for age, masculinity and fathering, but lower for attractiveness, than nulliparous women. Irrespective of reproductive status, beards were judged as looking more dominant than clean-shaven faces. Study 2 used a within-subjects design (N = 53) among women surveyed during pregnancy and three months post-partum. Judgments of parenting skills were higher for bearded stimuli during pregnancy among women having their first baby, whereas among parous women parenting skills judgments for bearded stimuli were higher post-partum. Our results suggest that mothers are sensitive to beardedness as a masculine secondary sexual characteristic that may denote parental investment, providing evidence that women's mate preferences could reflect sexual selection for direct benefits.

Check also Mating Strategies and the Masculinity Paradox: How Relationship Context, Relationship Status, and Sociosexuality Shape Women’s Preferences for Facial Masculinity and Beardedness. Rebecca E. Stower et al. Archives of Sexual Behavior, Apr 23 2019.

Rewritable fidelity: Male voles readily form new pair-bonds; repeated pair-bond dissolution didn't negatively impact affect nor behavior toward pups; older males spent less time with strange females

Rewritable fidelity: How repeated pairings and age influence subsequent pair-bond formation in male prairie voles. William M. Kenkel et al. Hormones and Behavior, Volume 113, July 2019, Pages 47-54.

•    Male prairie voles readily form new pair-bonds at least ten times.
•    Repeated pair-bond dissolution did not negatively impact affect.
•    Male voles did not show experience-related changes in paternal behavior.
•    Older males associated less with strange females.

Abstract: The prairie vole has proven a valuable animal model for the neurobiological study of social monogamy and pair bonding. Previous research has focused almost exclusively on virgin prairie voles forming pair-bonds for the first time – a paradigm with limited relevance to human social behavior. In the present study, we used stud males to assess the impact of repeated pair-bond formation and dissolution on the behaviors and neurobiology relevant to subsequent pair-bond formation. Stud males were tested for behavioral and neurobiological effects of repeated pair-bonding after the 1st, 5th, and 10th pairing. Aged breeder males that experienced minimal pair-bond dissolution were included to control for the effects of aging. Results showed that male prairie voles readily form new pair-bonds after repeated pair-bond dissolution. In terms of social monogamy, old age was associated with males spending less time in close social contact with unfamiliar females. There were no effects of age nor number of lifetime pairings on depressive-like behavior or paternal behavior toward pups. Within the brain, the patterns of oxytocin (OTR) and vasopressin type 1a (V1aR) receptors were largely unaffected, with the following exceptions: 1) males with only a single pairing had higher OTR densities in the paraventricular thalamus and bed nucleus of the stria terminalis; 2) there was an age-related increase in the density of OTR in the caudate putamen and an age-related decline in the density of V1aR in the cortical amygdala. The present findings have translational relevance to human social behavior in the context of aging and social experience.

Preregistration... Comparing Dream to Reality: We observed deviations from the plan in all studies, and, more importantly, in all but one study, at least one of these deviations was not fully disclosed

Claesen, Aline, Sara L. B. T. Gomes, Francis Tuerlinckx, and wolf vanpaemel. 2019. “Preregistration: Comparing Dream to Reality.” PsyArXiv. May 9. doi:10.31234/

Abstract: Doing research inevitably involves making numerous decisions that can influence research outcomes in such a way that it leads to overconfidence in statistical conclusions. One proposed method to increase the interpretability of a research finding is preregistration, which involves documenting analytic choices on a public, third-party repository prior to any influence by data. To investigate whether, in psychology, preregistration lives up to that potential, we focused on all articles published in Psychological Science with a preregistered badge between February 2015 and November 2017, and assessed the adherence to their corresponding preregistration plans. We observed deviations from the plan in all studies, and, more importantly, in all but one study, at least one of these deviations was not fully disclosed. We discuss examples and possible explanations, and highlight good practices for preregistering research.

Rolf Degen summarizing: Men respond to all kinds of womanly stimuli with a rise in testosterone, which may not even subside with age

Human reproductive behavior, life history, and the Challenge Hypothesis: A 30-year review, retrospective and future directions. Peter B. Gray et al. Hormones and Behavior, May 25 2019.

•    Reviews research on human life histories and the Challenge Hypothesis.
•    We conducted a citation analysis of 400 Google Scholar citations in the human literature, identifying key patterns.
•    We review findings within several domains: competition, courtship and sexual behavior, and partnerships and paternal care.
•    We discuss extensions of the Challenge Hypothesis to juvenile and senescent life stages.
•    We discuss how research on testosterone administration provides causal insight into effects of testosterone in humans.

Abstract: The Challenge Hypothesis (Wingfield et al., 1990) originally focused on adult male avian testosterone elevated in response to same-sex competition in reproductive contexts. The purpose of the present paper is to demonstrate how the Challenge Hypothesis has shaped ideas about human life histories. We conduct a citation analysis, drawing upon 400 Google Scholar citations in the human literature to identify patterns in this body of scholarship. We cover key factors, such as context and personality traits, that help explain variable testosterone responses such as winning/losing to adult competitive behavior. Findings from studies on courtship and sexual behavior indicate some variation in testosterone responses depending on factors such as motivation. A large body of research indicates that male testosterone levels are often lower in contexts of long-term committed partnerships and nurturant fathering and aligned with variation in male mating and parenting effort. As the Challenge Hypothesis is extended across the life course, DHEA and androstenedione (rather than testosterone) appear more responsive to juvenile male competitive behavior, and during reproductive senescence, baseline male testosterone levels decrease just as male life history allocations show decreased mating effort. We discuss how research on testosterone administration, particularly in older men, provides causal insight into effects of testosterone in humans, and how this “natural experiment” can be viewed in light of the Challenge Hypothesis. We synthesize central concepts and findings, such as an expanded array of costs of testosterone that inform life history tradeoffs between maintenance and reproductive effort, and we conclude with directions for future research.

People are unable to self-project into deteriorated versions of themselves; this is not based on similarity in mind or body, as say philosophical & psychological theories

De Freitas, Julian, and George Alvarez. 2019. “Struggling to Imagine Ourselves.”  PsyArXiv. May 11. doi:10.31234/

Abstract: The uniquely human ability to imagine alternate versions of ourselves draws on specialized neural networks and plays a critical role in planning and decision making. But is there any constraint on our ability to self-project into a remembered or anticipated version of ourselves? And if so, might this constraint also affect our ability to relate to others? Here we show that people are unable to self-project into deteriorated versions of themselves. This psychological roadblock is not based on similarity in mind or body, as current philosophical and psychological theories predict, but on an overlapping cognitive template— in order to feel that someone is you, you have to attribute to them a shared essence. Moreover, individual differences in how people identify with different versions of themselves predict their ethical opinions, including endorsement of abortion or assisted death, suggesting that the capacity for self-projection also constrains people’s moral judgments about others.

An association between women's physical attractiveness and the length of their reproductive career in a nationally representative sample

An association between women's physical attractiveness and the length of their reproductive career in a prospectively longitudinal nationally representative sample. Satoshi Kanazawa. American Journal of Human Biology, May 23 2019.

Objectives: Why is physical attractiveness more important for women's mate value in long‐term mating than in short‐term mating? This article replicates Bovet et al.'s (Journal of Evolutionary Biology. 2018; 31:229–238) recent finding that physically attractive women have a later expected age of menopause.

Methods: I analyzed the prospectively longitudinal, nationally representative sample of women in the National Child Development Study, applying t‐test and multiple regression analyses.

Results: Analyses showed that girls rated physically attractive at age 7 underwent menarche 3.12 months earlier than other girls, and they had 32% smaller odds of having undergone menopause before age 51. The results suggest that more physically attractive women have longer reproductive careers, explaining why physical attractiveness may be a more important determinant of women's mate value in long‐term mating than in short‐term mating.

Conclusions: Women's physical attractiveness predicts the timing of menarche and menopause, thereby the length of their reproductive careers.