The reduction in the sex difference in physical size since the australopithecines and the corresponding reduction in the variability across hominid brain volumes make it very likely that the average brain size of our male and female ancestors has converged since the emergence of HomoRead more at location 6925
Pakkenberg and Gundersen (1997) found that in comparison with women’s brains, men’s brains, on average, are 13% heavier, occupy 15% more volume, and contain 16% more neurons, among other differences.Read more at location 6928
M. Leonard et al. (2008) found that the overall brain size of more than 9 out of 10 men was larger than that of the average woman.Read more at location 6930
The 10% male advantage in brain size is found in newborns and continues into childhood, juvenility, and adolescence;Read more at location 6934
Overall, men have more gray matter (neuronal cell bodies and dendrites that collect information from other cells) and white matter (neuronal axons that transmit information to other cells) than women.Read more at location 6941
The areas of enhanced thickness in women are associated with language skillsRead more at location 6947
One of the more controversial findings concerns the corpus callosum, the bundle of axons that allows communication across the left and right hemispheres. De Lacoste-Utamsing and Holloway (1982) reported that the back portion of the callosum was shaped differently in men and women and that relative to overall brain weight was larger in women. They speculated “that the female brain is less well lateralized—that is, manifests less hemispheric specialization—Read more at location 6968
Inferences about the influence of prenatal hormones on human sex differences in brain organizationRead more at location 6991
These studies have focused on whether prenatal exposure to testosterone or estrogens (which can be converted to testosterone) results in male-typical patterns of brain organization or functioning.Read more at location 6995
More men than women are left-handed, and language and spatial functions tend to be more strongly localized in the left and right hemispheres, respectively, in men and distributed across both hemispheres in women (McGlone, 1980; Witelson, 1976, 1991). Kelso, Nicholls, Warne, and Zacharin (2000) found more left-handers and better nonverbal than verbal abilities for girls and women with CAH,Read more at location 6999
An intriguing example is provided by a brain imaging study of amygdala activation, which is involved in the processing of emotionally and sexually laden information, when individuals with CAH viewed facial expressions that conveyed neutral and negative affect (i.e., fear or anger; Ernst et al., 2007); L.Read more at location 7009
When reflecting on or describing themselves (e.g., completing “I am …”), women are more likely than men to view themselves in terms of close relationships with family members or friends, whereas men are more likely to view themselves as members of groups or teams (Gabriel & Gardner, 1999).Read more at location 7048
girls and women appear to be more aware of nuances in their feelings and emotions than boys and men and have better memories for the details of emotionally charged personal experiences (Barrett, Lane, Sechrest, & Schwartz, 2000).Read more at location 7053
My interpretation is that girls and women are better able to use awareness of their feelings as a social barometer,Read more at location 7058
In general, girls and women tend to reflect on their behavior and traits more frequently than do boys and men across many domains (Fejfar & Hoyle, 2000), and their bodies are a common area of reflectionRead more at location 7080
Female–female competition is not the only potential source of sex differences in individual-level folk competencies.Read more at location 7107
Girls and women are better than boys and men at interpreting and sending nonverbal social messages, including skill at reading emotional states conveyed in facial expressions, gesture, and body language and in generating nuance in the social use of these forms of communication (Buck, Savin, Miller, & Caul,1972; J. A. Hall, 1978, 1984; J. A. Hall & Matsumoto, 2004; McClure, 2000; Rosenthal, Hall, DiMatteo, Rogers, & Archer, 1979; van Beek & Dubas, 2008; Wagner, Buck, & Winterbotham, 1993).Read more at location 7121
amygdala is among the core brain systems involved in the processing of emotion-laden information and is structurally and functionally different in women and men (e.g., Goldstein et al., 2001; Kilpatrick et al., 2006).Read more at location 7166
After correcting for the sex difference in brain size and size of the frontal cortex, the social–emotional processing areas of the prefrontal cortex are larger in women than in menRead more at location 7170
In addition to the sex differences in proportional size of the amygdala (larger in men) and ventromedial prefrontal cortex (larger in women), these regions are interconnected differently in women and men (Kirkpatrick et al., 2006; Tranel, Damasio, Denburg, & Bechara, 2005). There appears to be greater functional connectivity between these regions in the right hemisphere for men and the left hemisphere for women.Read more at location 7174
prenatal exposure to male testosterone may bias the later functioning of the amygdala (Ernst et al., 2007), and men’s larger amygdala may be due to the pubertal increase in testosterone (Neufang et al., 2009).Read more at location 7202
Girls talk more than boys during the first 2 years of life and during the juvenile period (about 10–13 years), but boys may talk more during adolescence (Leaper & Smith, 2004). AtRead more at location 7253
Pragmatics refers to the use of language in social contexts. Boys and men tend to use language to attempt to assert their social dominance,Read more at location 7257
Relative to boys and men, girls and women have advantages for many basic language-related skills, including the length and quality of utterances (e.g., in their utterances women show standard grammatical structure and a correct pronunciation of language sounds more frequently than do men), the ease and speed of articulating complex words, the ability to generate strings of words, the speed of retrieving individual words from long-term memory, and skill at discriminating basic language sounds from one another (R. A. Block, Arnott, Quigley, & Lynch, 1989; D. F. Halpern, 2000; Hampson, 1990a; Hyde & Linn, 1988; Majeres, 2007).Read more at location 7285
women are predicted to invest more in their children than are men, as is the case for mammals in general (Clutton-Brock, 1991). Ample support for this prediction was provided in chapter 6 of this volume.Read more at location 7498
A less obvious prediction is that men will show a bias for male kin, especially when their group is engaged in frequent intergroup conflict;Read more at location 7501
boys’ groups are better integrated than are girls’ groupsRead more at location 7535
girls and women are more reciprocal in dyadic relationshipsRead more at location 7543
I assume gay men are discriminated against by other men because of an implicit assumption that gay men’s contributions to male–male coalitional competition will be limited; whether this is the case remains to be determined.Read more at location 7555
intergroup cooperation was lower for men but not for women when the ingroup and the outgroup were equally matched (L. E. Davis et al., 1996).Read more at location 7578
social identification enables the formation of larger and therefore more competitive social groups, and one of the core selection pressures for the establishment and maintenance of large competitive groups is coalitional male–male competition.Read more at location 7621
If this hypothesis is correct, then social identification with competitive groups (e.g., a sports team, a nationality) should be more easily instantiated in men than in women,Read more at location 7623
As with ingroup and outgroup dynamics, there are probably more similarities than differences in women’s and men’s social identification processes.Read more at location 7626
