Samstag, 15. Oktober 2016

Gorillas in our midst? Human sexual dimorphism and contest competition in men

Gorillas in our midst? Human sexual dimorphism and contest competition in men
Alexander K Hill, Drew H Bailey, David A Puts (2016)


The literature on human sexual selection has historically focused on the role of female mate choice, but cumulating experimental, correlational, and cross-cultural evidence suggests that male contest competition may have been more influential in shaping men's phenotypes. Cross-species comparison has shown similarities between humans and our closest extant phylogenetic relatives, the Great Apes, in male–male aggression, and archeological evidence also indicates a great antiquity for male–male violence. Compared to women, men possess substantially greater muscle mass, strength, cranial robusticity, physical aggression, pain tolerance, risk-taking, weapons use, and participation in coalitional aggression. Men also exhibit displays of physical prowess and acuity to the formidability of male conspecifics, as well as possessing a suite of traits, such as facial hair and low vocal pitch, that increase perceptions of dominance. These traits are consistent with having been shaped by contest competition over mates: they are sexually dimorphic, appear at sexual maturity, and predict success in male contests as well as success in mating and reproduction. While alternative explanations for some of these sexually dimorphic traits are possible, contest competition among males throughout human evolutionary history is the most parsimonious.

Freitag, 14. Oktober 2016

Tele-Akademie - Prof. Gerhard Roth

Prof. Gerhard Roth spricht zum Thema "Bildung braucht Persönlichkeit" (9.10.2016)

[Naja. Die Aussage Gerhard Roths, dass Gene auf den Ausprägungsgrad der Intelligenz einen untergeordneten Einfluss ausüben, dürfte kaum wissenschaftlich gestützt sein. Meines Erachtens räumt er mit dieser Aussage vorgeburtlichen Umwelteinflüßen eine deutlich zu große Bedeutung ein. In Extremfällen, in denen massiv schlechte Entwicklungsbedingungen im Mutterleib vorhanden sind (bzw. im Fall von extremen Frühgeburten), dürfte dies zu einer erheblichen lebenslangen Veränderung des Intelligenzausprägungsgrad (in negative Richtung) führen. Gerhard Roth schließt aber anscheinend aus schwer nachvollzierbaren Gedankengängen, dass 30 Prozent der Intelligenzvariation aus genetischer Variation, 20 Prozent aus vorgeburtlichen Umwelteinflüssen und die übrige Hälfte aus nachgeburtlichen Umwelteinflüssen (die zum größten Teil in der frühen nachgeburtlichen Phase wirken sollen??) erklärt werden können.]

Self-Esteem and Shame:

"Earlier, I described Shame as the subjective marker of social failure. ... Consistent with this perspective, clinical evidence indicates that interindividual differences in the ease with which Shame is elicited are largely the product of differing life histories (Lewis 1987). Significantly, successes and failures seem to have a cumulative effect -- repeated (and early) failures lower the Shame threshold (Miller 1985). Moreover, both clinical and experimental results indicate that the propensity to experience Shame is negatively correlated with self-esteem (Retzinger 1991; Miller 1985). Self-esteem can be conceptualized as the generalized assessment of self as relatively successful or unsuccessful, a summation of the events which constitute Ego’s self-perceived successes and failures to date. Self-esteem influences whether events are seen as constituting relatively greater or lesser successes or failures, and it is this which determines the ease of elicitation of Shame. In turn, because Shame affects the salience of risk and benefit during decision making, by setting the threshold for experiencing Shame, self-esteem indirectly determines the likelihood that benefit will be maximized or risk will be avoided. Self-esteem thus operates to create a consistent situation-sensitive strategy, linking life experience to immediate decisions."

Daniel M. T. Fessler (2001)
"confidence is part of our genetic makeup; it evolved over thousands of generations as a mental tool to guide our decision-making around risk."

Geoffrey Miller

[See also: The role of shame and self-esteem in risk taking by Daniel Fessler, 2001]

Language as a mighty "intelligence amplifier":

>Among terrestrial vertebrates, birds and mammals generally exceed both amphibians and ‘‘reptiles’’ with respect to cognitive abilities. Among birds, corvids and parrots stand out in this regard with behavioral flexibility, innovation rate, tool use and tool fabrication, and also with respect to truly mental abilities such as logical reasoning and mirror self-recognition––at least in one corvid species. 
Several groups of mammals, like dolphins and whales, dogs, elephants, and bears (just to mention a few) show signs of high intelligence at least in some cognitive domains. Primates on average exhibit an intelligence superior to all other mammals. Among primates, there is a rather clear-cut ranking order in intelligence, from the prosimians to monkeys and to the great apes. Except a few species (e.g., capuchins), the great apes exhibit at least some aspects of cognitive and mental abilities not found in monkeys regarding tool fabrication, insight into causal mechanisms, mirror recognition, theory of mind, knowledge attribution, metacognition, and consciousness. 
However, humans, even under the most critical aspects, are superior to other animals in all cognitive functions, no matter how astonishing the achievements of the latter may be. The most clear-cut differences between humans and non-human primates lies in two abilities that are interconnected: planning abilities and a syntactic-grammatical language. When we compare the cognitive-mental abilities of the most intelligent non-human animals with those of humans, then we find that they roughly correspond to the abilities of children aged 2 1/2-5. As for linguistic abilities, chimpanzees and gorillas equal a 3-year-old child, while with respect to psychosocial abilities (empathy, theory of mind, etc.) they may be equivalent to those of a 5-year-old child. In light of these empirical findings, the standard question of whether human intelligence differs qualitatively or only quantitatively from the non-human one, may ironically be transformed into the question about whether, with respect to cognitive functions, an adolescent or adult is qualitatively or only quantitatively superior to a 3–5-year-old child. Besides maturation of social competences, the most decisive feature that distinguishes humans from nonhuman animals is the appearance of a syntactical-grammatical language at age 2 1/2, which is paralleled by an enormous increase in the capacity of working memory and, consequently, intelligence, i.e., novel problem solving. 
Therefore, the ‘‘rubicon’’ between animal and human intelligence seems to be the evolution of the syntactical-grammatical language, which is essentially bound to an increase in the ability to mentally manipulate processes (first actions, then thoughts, then words) in the temporal domain. Once evolved, human language served as a mighty ‘‘intelligence amplifier,’’ as was later development of writing and invention of the computer.<

The long evolution of brains and minds
Gerhard Roth (2013)