Category “Homo sapiens sapiens”

What Do Women Want?

Comments (7)

3 different ways to identify an emotion

(1) The physiological brain state;

(2) The way an individual describes the feeling;

(3) The behaviour the feeling leads to.

Comments (2)

Regarding the Phylogeny of Tickle-Induced Laughter

TickledChimpanzee

{Ross, M.D. et al. (2009), 'Reconstructing the evolution of laughter in great apes and humans', Current Biology, 19, p. 1106-1111}

{Ross, M.D. et al. (2009), 'Reconstructing the evolution of laughter in great apes and humans', Current Biology, 19, p. 1106-1111}

Leave a Comment

Resource-Related Deceptive Alarm

monkey_capuchin

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”.

Comments (1)

Altruism, Inter-group conflict, Demography

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”.)

skillaccumulationdemography1An 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:

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

humanwarfaremortalitySummary statistics: Fraction of total mortality due to warfare.

Leave a Comment

Laetoli footprints, 3.6 Ma

laetoli_footprints

Leave a Comment

Human Evolution

humanevolutiontimeline

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

Leave a Comment

Overview of Dominant Approaches to Human Behavioural Evolution

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.

Comments (2)

Mating behaviour

‘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:

sociosexuality_gender

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

sexuality_environment

Leave a Comment