Category: Homo sapiens sapiens

“Women’s Desire Is Driven By Narcissism“

(1) The physiological brain state;

(2) The way an individual describes the feeling;

(3) The behaviour the feeling leads to.

A new report by {Wheeler, B. (June 2009), Proceedings of the Royal Society B} exposes ‘R.R.D.A.’ amongst capuchin monkeys in Iguazá National Park, Argentina. The deceitful lil’ buggers proffer two-syllable cooing sounds, normally uttered in response to danger, for “no apparent reason […] other than to chase the other individuals off the food platform”.

Well, humans, hasn’t it been an interesting week in the modelling of your behaviour?

(1) To start off, {Powell et al. (2009), Science, 324, p. 1298-1301} convincingly argue that it was population density, not genetic change, that got the ball rolling on your symbolic and technological complexity in the Late Pleistocene: (z measures “level of ability at some cultural skill or in some cultural domain”.)

An illustration, from a single iteration and shown at 25-generation intervals, of the spatial structuring of skill accumulation in a heterogeneous subpopulation density world. The left side of each subplot is populated at density Dhigh (0.02) and the right side at density Dlow (0.002). Each subpopulation is marked by a circle, centered on the spatial location of the group and with diameter proportional to its mean z value. Regional mean z values are also given at the top of each subplot.

(2) And {Bowles, S.  (2009), Science, 324, p. 1293-1298} argues that it was mortality due to inter-group rivalry that gave rise to your  much-touted  costly individual altruism. Particularly interesting is his analysis of Pleistocene mortality rates resulting from inter-group conflict:

Sources of archaeological (filled squares) and ethnographic (filled dots) evidence on warfare and genetic (open dots) data on between-group differences.

Summary statistics: Fraction of total mortality due to warfare.

Kingston, J.D. (2007), ‘Shifting adaptive landscapes: Progress and challenges in reconstructing early hominid environments’, Yearbook of Physical Anthropology, 50, p. 20-28.

So, here’s an overview of current Schools of Thought tackling Human Behavioural Evolution:

School	Neo-Darwinistic Sociobiology	Human Behavioural Ecology	Environmental Psychology	Dual-Inverse Theory	Memetics
Focus of selection	Gene / individual / group	Individual / behaviour	Individual / behaviour / psychological mechanism	Individual / group / gene / culture variantPotential / predicted impact on genetic and cultural fitness	Meme / gene
Measure of natural selection	Reproductive success or proxy measure of fitness	Reproductive success of proxy measure of fitness (enegetic balance)	Potential / predicted impact on reproductive success / fitness	Potential / predicted impact on genetic and cultural fitness	Potential impact on genic and memic fitness
Methodology	Genic functionalism- construct genic level fitness enhancing / optimality models, test data against them	Test data against optimality models, ecological expectations / prediction models from behavioral ecology	Construct selection scenarios and describe predicted fitness increasing strategies, test with datasets	Construct mathematical and conceptual models and simulations, sometimes test with datasets	Construct selection scenarios, controlled thought experiments
Core causes of evolution of human behaviour	Genetic evolution produces both human general behavioural capacities and specific behavioural patterns / strategies	Behaviour and behavioural strategies arise from adaptation to ecological and other selective pressures	Psychological mechanisms (and thus behaviour) arose/arise through adaptation to pressures of the Environment or Evolutionary Adaptiveness (Pleistocene) and Adaptivity Relevant Environments	Gene-culture coevolution results in patterns of complex, symbolic and linguistic human behaviour	Selfish meme replication and meme-gene coevolution result in most human behaviour
Basic premise(s)	Humans are very complex and highly social animals whose behaviour is best analyzed via Neo-Darwinian approaches	Humans, while highly adaptable, can be modeled using same premises as other animals, socioecological contexts drive most selection pressures	Human universals and human behavioural strategies are reflections of adapted modules (psychological mechanisms) in the mind	Humans are under genic and group selection for physical and cultural traits; culture and genetic co-evolve via natural selection	Memes/memeplexes are primarily responsible for human behavioural variation and culture
Data	Ethnographic datasets, observations, comparisons with other animals especially primates, fossil record	Behaviour observations, physiological and ecological measurements, ethnographic datasets	Questionnaires, surveys, interviews, demographic and behavioural datasets, public records	Ethnographic datasets, mathematical models	Popular ethnography, survey and interviews, general cultural information

Adapted from Fuentes, A. (2009), Evolution of Human Behavior, Oxford University Press, Oxford/New York, p. 60-61.

‘Sociosexuality’ measures mating style preference, expressed on a continuum from extreme monogamy (low index) to extreme polygamy (high index).  A 25-language 48-nation >14.000-participant study (Schmitt, David (2005), ‘Sociosexuality from Argentina to Zimbabwe: A 48-nation study of sex, culture, and strategies of human mating’, Behavioral and Brain Sciences, 28, p. 247-311) found that men are consistently more enthusiastic about polygamy than women:

That much is expected. In addition, the study found that elevated male/female ratios and environmental stressors correlate with lower sociosexuality: