Transcript EP review

Kurzban & Houser (2005): Experiments investigating
cooperative types in humans: A complement to evolutionary
theory and simulations. PNAS.
Boris & Patrick
“The evolution of cooperation in groups of non-kin in
humans has been … the subject of debate ...
...fundamental questions remain about the … nature
of the cognitive mechanisms that underpin human
cooperative psychology and whether there are
stable individual differences in these mechanisms.
Experimental results of the kind reported here can
be useful for clarifying whether the assumption of
stable types in the realm of human cooperation as
assumed by simulations is justified, and, if it is, how
best to characterize these types.”
Kurzban & Houser (2005): Experiments investigating
cooperative types in humans: A complement to evolutionary
theory and simulations. PNAS.
Boris & Patrick
“In line with types used in simulations and
observed in other experimental contexts, we
consider the hypothesis that people are one
of three stable types: ”
• Cooperators: contribute to generating group
benefits at a cost to self
• Free-riders: who do not incur these costs
• Reciprocators: who respond to others’
behavior by using a conditional strategy
(such as tit-for-tat)
Von Rueden et al (2008): The multiple dimensions of male
social status in an Amazonian society. Evol. Hum. Behav.
Maddie & Caitlane
Predictions:
Physical size  winning dyadic fights
Number of allies  winning
group conflicts
Acculturation  community
influence
Prosocial behavior  community
influence
Social status will increase until 40’s,
then decline, with each proxy
declining at a different rate
Fiddick & Erlich (2010): Giving it all away: altruism and
answers to the Wason selection task. Evol. Hum. Behav.
Ngoc & Laura
Our minds consist primarily of “a constellation of
specialized mechanisms that have domain-specific
procedures, operate over domain-specific representations,
or both” Cosmides and Tooby (1994)
Cosmides 1989: cheater detection is one such
mechanism. Used Wason selection task.
Subsequent studies: altruist detection is another such
mechanism, perhaps subserving both.
Problem 1: confounds in instructions (“giving it all away”)
Problem 2: altruist detection makes no theoretical sense
Musso et al (2003): Broca’s area and the language instinct.
Nature Neuroscience.
Kyle & Victor
Purpose: To investigate the system underlying the
acquisition of new linguistic competence
Chomsky hypothesis = Universal Grammar
Alternative hypothesis: The human
mind is a general learning tool without
specialized structures
Prediction: by Chomsky hypothesis,
individuals should use Broca’s area in
learning new ‘real’ language but not in
learning new ‘unreal’ language
Schug et al (2010): Emotional expressivity as a signal of
cooperation. Evolution & Human Behavior. Carol & Adrian
Hypothesis: emotional expressivity is a honest (reliable)
signal of a cooperative disposition because emotional
responses are involuntary and cannot be faked.
More specifically: cooperators are
likely to show more emotion,
both positive and negative.
Involuntary nature of emotional
expression is taken as a given,
not treated as adaptive.
Presumably the ability to pick up on these
signals would be adaptive, but that’s not tested here, only
whether the degree of emotional expression predicts
cooperativeness.
Healy & Ellis (2007): Birth order etc: Tests of the familyniche model of personality. Evolution & Human Behavior.
Maddie & Dylan
Test hypothesis about personality
differences between 1st- and 2ndborn siblings.
Primary hypothesis: 1st-borns are
more responsible, achieving, etc,.
second borns more rebellious and
unconventional.
Secondary hypothesis: 2nd-born
males hypomasculinized, therefore
bigger differences between male
than female sibling pairs.
Healy & Ellis (2007): Birth order etc: Tests of the familyniche model of personality. Evolution & Human Behavior.
Maddie & Dylan
Test hypothesis about personality
differences between 1st- and 2ndborn siblings.
Primary hypothesis: 1st-borns are
more responsible, achieving, etc,.
second borns more rebellious and
unconventional.
Secondary hypothesis: 2nd-born
males hypomasculinized, therefore
bigger differences between male
than female sibling pairs.
Salmon et al (2008): Ancestral mechanisms in modern
environments: Impact of competition and stressors on body
image and dieting behavior. Human Nature.
Tiffany & Alex
Evolutionary hypothesis:
anorexia is an adaptation for
exerting control over reproduction,
specifically by suspending
menstruation (ovulation).
Idea is that in times of unfavorable
social or ecological conditions,
woman could delay reproduction
until situation or ability to deal with
it improves. In short, in EEA,
adjusting body fat was a way of
modulating reproduction.
Miller – Costly Display Theory
Culture is more than a system for transmitting useful
technical knowledge and group-benefiting traditions down
through the generations. It can also “be considered an
arena for various courtship displays in which individuals try
to attract and retain sexual partners. When a young male
rock star stands up in front of a crowd and produces some
pieces of human ‘culture’ known as songs, he is not
improving his survival prospects. Nor is he engaging in
some bizarre maladaptive behaviour that requires some
new process of ‘cultural evolution’ to explain. Rather, he is
doing something that fulfils exactly the same function as a
male nightingale singing or a male peacock showing off his
tail. He is attracting sexual partners”.
Miller 1999
Question: Why is most publicly generated ‘cultural’
behaviour is produced by young males points towards its
courtship function.
Miller – Costly Display Theory
“This cultural courtship model proposes that sexual selection
through mate choice by both our male and female ancestors
was a major evolutionary force in shaping human culture,
i.e. the genetically inherited capacities for behaviours such
as language, art, and music. These behaviours, according
to this model, function mainly as courtship displays to attract
sexual partners, and show many of the same design
features shared by other courtship displays in other
species. In short, human culture is mainly a set of
adaptations for courtship. This hypothesis doesn’t really
come from Nietzsche, of course, or from Freud. Rather, it is
a relatively simple application of standard Darwinian sexual
selection theory to a somewhat puzzling set of behavioural
phenomena in one rather pretentious species of primate”.
Miller 1999
Nettle & Clegg (2006): Schizotypy, creativity and mating
success in humans. Proc. Royal Society. Grant & Brooke
Miller’s hypothesis: Costly
displays of quality function
to attract mates
Prediction: artistic
production correlated with
high number/quality of
sexual partners
Gerdes et al (2009): Spiders are special. Evolution &
Human Behavior.
Michael, Alex & Lindsay
Preparedness hypothesis: we should be strongly inclined
to fear dangerous things (learn quickly etc).
Authors examine an apparent exception to this
hypothesis: spiders are more feared than bees & wasps
despite being less dangerous.
Positive aspects of bees
(especially in EEA) might be a
partial answer to this paradox.
Authors just raise a problem,
but provide no answers.
Newson et al (2007): Influences on communication
about reproduction: the cultural evolution of low fertility.
Evolution & Human Behavior.
Kyle & Victor
Hypothesis: kin influence individuals to make decisions
that advances the individual’s fitness and their relatives’
inclusive fitness.
Proxy is fairly weak, as they rely on role-playing about
what a woman might do rather than providing actual data
on this point.
But it is a clear evolutionary alternative to the standard
(r vs k selection) hypothesis that decrease in fertility in
modern societies reflects a shift to a strategy of investing
more in a few kids rather than having lots of kids.
Model for attractiveness of indicator trait and
prevalence of schizophrenia