Psychology, Sex and Gender: Links

General Psychology

Disorders

Borderline Personality Disorder

Ryden G et al. Borderline Personality Disorder and Autism Spectrum Disorder in Females — A Cross-Sectional Study. 2008. Clinical Neuropsychiatry. http://www.clinicalneuropsychiatry.org/pdf/04_ryden_hetta.pdf

Sprague et al. Borderline Personality Disorder as a Female Phenotypic Expression of Psychopathy? 2012https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323706/

Skodol, Bender. Why Are Women Diagnosed Borderline More Than Men? 2003https://link.springer.com/article/10.1023/A:1026087410516

Sansone and Sansone. Gender Patterns in Borderline Personality Disorder 2011 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3115767/

https://www.borderlinepersonalitytreatment.com/borderline-personality-disorder-women.html

Sex and Gender

Alexander, Hines. Sex differences in response to children’s toys in nonhuman primates. 2002. http://www.ehbonline.org/article/S1090-5138(02)00107-1/pdf

Herzog Harold A. Gender Differences in Human–Animal Interactions: A Review 2007 http://paws.wcu.edu/herzog/Gender.pdf Full pdf

Baileya, et al. Finger length ratio (2D:4D )correlates with physical aggression in men but not in women http://web.missouri.edu/~segerti/2210/BaileyHurdfingerlength.pdf

Boesch C Sex differences in the use of natural hammers by wild chimpanzees: A preliminary report 1981 http://www.sciencedirect.com/science/article/pii/S0047248481800498

Abstract

The chimpanzees of the Tai National Park, Ivory Coast, use clubs and stones to open different species of nuts. An intriguing sex difference has been observed in this behavior. It is almost exclusively females that open Coula nuts directly in the tree and crack the very hard Panda nuts. Both techniques are difficult and imply either anticipating the need of a hammer and its transport, or exact positioning of the nut and precise dosage of the hits. The efficiency of females is superior to that of males in the technique of cracking Coula nuts on the ground, which is performed by both sexes. Possible implications for the evolution of tool-use in humans are discussed.

Guadalupe et alia. Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex. 2016https://link.springer.com/article/10.1007%2Fs11682-016-9629-z

Abstract

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders.

Hines.M et al. Early androgen exposure and human gender development 2015 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350266/

Leonard, C M et al. Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy. 2008. https://academic.oup.com/cercor/article/18/12/2920/367003

Abstract

Biological and behavioral differences between the sexes range from obvious to subtle or nonexistent. Neuroanatomical differences are particularly controversial, perhaps due to the implication that they might account for behavioral differences. In this sample of 200 men and women, large effect sizes (Cohen’s d > 0.8) were found for sex differences in total cerebral gray and white matter, cerebellum, and gray matter proportion (women had a higher proportion of gray matter). The only one of these sex differences that survived adjustment for the effect of cerebral volume was gray matter proportion. Individual differences in cerebral volume accounted for 21% of the difference in gray matter proportion, while sex accounted for an additional 4%. The relative size of the corpus callosum was 5% larger in women, but this difference was completely explained by a negative relationship between relative callosal size and cerebral volume. In agreement with Jancke et al., individuals with higher cerebral volume tended to have smaller corpora callosa. There were few sex differences in the size of structures in Broca’s and Wernicke’s area. We conclude that individual differences in brain volume, in both men and women, account for apparent sex differences in relative size.

Moore R W et al. Abnormalities of sexual development in male rats with in utero and lactational exposure to the antiandrogenic plasticizer Di(2-ethylhexyl) phthalate. 2001 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1240240/   Full PDF

PHOENIX CH et al Organizing action of prenatally administered testosterone propionate on the tissues mediating mating behavior in the female guinea pig. 1959 https://www.ncbi.nlm.nih.gov/pubmed/14432658

Ritchie, S et al. Sex differences in the adult human brain: Evidence from 5,216 UK Biobank participants 2017 http://biorxiv.org/content/biorxiv/early/2017/04/04/123729.full.pdf

Ruigrok, Amber N.V. A meta-analysis of sex differences in human brain structure 2013 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3969295/

de Vries, Geert J. 1Sex Differences in the Brain: the Relation between Structure and Function 2009 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3932614/

de Waal Frans B.M. Sex differences in the formation of coalitions among chimpanzees 1984 http://www.sciencedirect.com/science/article/pii/0162309584900049

Abstract

Observations were made of spontaneous coalition formation during aggressive encounters among chimpanzees in a large, semicaptive colony. The analysis of several thousand instances, collected over a period of 5 years, revealed striking differences between adult males and females. Male coalitions changed over time and showed little connection with social bonds, as measured by associative behaviors. Females, in contrast, showed stable coalitions, which strongly overlapped with their social bonds. Also, coalition formation with males and females differed. Females were treated on the basis of their coalitions and bonds with others in the group; males were not.

A single difference in proximate social goals is proposed as an explanation for these and other differences. Male coalitions seem to serve status competition. Males may form flexible coalitions in order to rise in rank, and may adopt the role of group protector in order to maintain a high rank. Female coalitions seem to serve the protection of particular individuals, namely, friends and kin. A similar sex difference has been reported for human coalition formation in experimental game situations.

Wallen K. The Organizational Hypothesis: Reflections on the 50th anniversary of the publication of Phoenix, Goy, Gerall, and Young (1959). https://www.ncbi.nlm.nih.gov/pubmed/19446072

Whiten, Andrew  et al. Conformity to cultural norms of tool use in chimpanzees  2005 https://search.proquest.com/central/docview/204572350 full pdf

Wolf CJ et al. Effects of prenatal testosterone propionate on the sexual development of male and female rats: a dose-response study. 2002 https://www.ncbi.nlm.nih.gov/pubmed/11752687

Abstract

Testosterone plays a major role in male sexual development. Exposure of females to testosterone in utero can induce masculine characteristics such as anovulation, increased anogenital distance (AGD), absence of nipples, retention of male-like tissues, and agenesis of the lower vagina. In addition, high levels of androgens during fetal development can lead to toxic effects such as reduced litter size and viability. The study of the effects of testosterone administration during sexual differentiation provides a foundation for understanding the effects of environmental androgens on fetuses, a sensitive subpopulation. In the current study, we investigated the ability of a range of concentrations of testosterone propionate (TP) administered prenatally to masculinize female and alter male offspring, and measured maternal and fetal T levels. Pregnant Sprague-Dawley rats were dosed by sc injection on gestational day (GD) 14-19 (GD 1= day of plug) with either corn oil (vehicle; 0.1 ml/rat) or with 0.1 ml of TP solution at 0.1, 0.5, 1, 2, 5, or 10 mg/0.1 ml. Parturition was delayed at 2, 5, and 10 mg TP, litter size was reduced at 5 and 10 mg TP, and pup weight was significantly reduced in both sexes at 0.5 mg TP and higher doses. Viability of offspring was unaffected at any dosage level. Androgenic effects seen at 0.5 mg TP in females included increased AGD at weaning and adulthood, reduced number of areolas and nipples, cleft phallus, small vaginal orifice, and presence of prostate tissue. This dose of TP elevated maternal T levels 10x but had no effect on fetal T levels. At 1 mg TP and above, female AGD on postnatal day (PND) 2 (or postcoital day 24 [gestation length = 22(1/2)]) was increased; areolas and nipples were virtually eliminated; levator ani muscle, bulbourethral glands, and seminal vesicles (2 mg TP and above) were present; none of the females developed a vaginal orifice and many females in the 1 and 2 mg TP dose groups developed a greatly distended, fluid-filled uterus after puberty. Maternal T levels at 1 mg TP were elevated 30x, and female fetal T levels showed an 80% increase. Male offspring displayed a reduced AGD and body weight on PND 2 at 0.5 mg TP and higher doses. These effects were not evident by weaning and male offspring displayed no malformations. We conclude that gestational administration of 0.5 and 1 mg TP masculinizes female offspring without greatly affecting pup viability or pregnancy of the dam. This study provides a useful model for in utero testing of environmental androgens for their potential to induce developmental abnormalities.

Wrangham RW et al. Sex differences in the behavioural ecology of chimpanzees in the Gombe National Park, Tanzania. 1980 http://europepmc.org/abstract/med/6934308

Abstract

All-day observations of focal individuals were analysed to compare grouping and ranging patterns and the proportion of time spent feeding by females and males; sexually receptive females were not included. Females spent most of their time alone, whereas males spent most of their time in parties with other males. Females travelled shorter distances than males, and spent their time in smaller core areas: when they joined parties, however, they often travelled outside their normal core areas. Grouping and ranging patterns appear to be related to foraging strategies in different ways in each sex. Females often joined parties for a short time only (< 1 1/2 h), apparently at rich food sources. Males tended to stay for longer, even though they then spent less time feeding than when alone. Spending all day in a party was associated with reduced feeding time for both sexes, but on these days ranging patterns differed between the sexes because males, but not females, travelled further when in parties. The results support the idea that the form of the chimpanzee social system is determined by the interaction of two different strategies: females attempt to forage so as to maximize net energy intake, while males sacrifice an optimal foraging strategy for the sake of reproductive competition.

Social Science

Huber J. A theory of family, economy, and gender. 1988 https://www.ncbi.nlm.nih.gov/pubmed/12281313

Smith, Paul Writing, General Knowledge, and Postmodern Anthropology 1999 http://theory.eserver.org/anthropology.html

Sparks  et al A reassessment of human cranial plasticity: Boas revisited http://www.pnas.org/content/99/23/14636.abstract?ijkey=f3uGSmr3wB0r.