Evolutionary Psychology 101
 Humans evolved to solve recurrent problems our
ancestors faced during the environment we evolved in:
Pleistocene hunter-gatherers.
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The mind is made up of many domain-specific
mechanisms= “modules.”
Modules solve problems repeatedly encountered by our
ancestors.
 Only problems that recur over and over again can be
subjected to natural selection. It takes a long time to
change gene frequencies. If a problem is relatively
rare, evolution can’t solve it by constructing a module.
Each module is specifically designed to solve
an adaptive problem: The mind as a Swiss
Army knife.
Evolutionary Psychology 101
 Modules are “dedicated intelligences” that receive
characteristic inputs and produce characteristic output.
 Modules operate unconsciously.
 E.g.:
Male fighting fish have a module
sensitive to the color or another male
(=input); when they see this, there is a
characteristic output (= aggression).
 This is a reflex: it operates without
conscious deliberation.
Modular Information processing domains:
David Geary, The Origin of Mind, 2005.
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Folk Psychology
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Self
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Individual
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Self awareness: Represent self as social being and have a sense of
persistence of self through time
Self schema: Knowledge of one’s own personality and relationships
with other people
Nonverbal behavior: e.g., postural cues
Facial expression
Language
Theory of Mind: Ability to infer intentions, beliefs, emotional states and
future behavior of individuals; no evidence in monkeys; controversial
in chimpanzees
Person Schema: Knowledge of specific other people and their
networks
Group
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Kin recognition: Mothers and babies recognize each other by smell;
children able to identify odor of full siblings, not half siblings or stepsiblings
In-group/Out-group
Modular Information processing domains:
David Geary, The Origin of Mind, 2005.
 Folk Biology
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All humans classify flora and fauna on basis of
morphology, behavior, growth patterns, and ecological
niche;
Disruptions of anterior temporal cortex disrupts ability to
name living but not non-living things. (Not conclusive)
 Folk Physics
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Systems sensitive to invariant features of physical space.
For humans, this includes ability to mentally represent
physical objects and manipulate the objects, as in tool use.
These may engage working memory: spatial intelligence.
Navigation via mental maps of routes and landmarks both
involve parietal cortex, but route task also involved
hippocampus. Posterior hippocampus of taxi drivers in
London larger than age-matched men. Volume correlated
with time spent as taxi driver (Maguire et al., 2000)
Characteristics of Implicit and Explicit
Cognitive Systems
Implicit System
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o
o
Explicit System
Unconscious
Conscious
Automatic
Controllable
Fast
Relatively slow
Evolved Early
Evolved Late
Common among animals
May be unique to
humans
Characteristics of Implicit and Explicit
Cognitive Systems
Implicit System
o Parallel Processing
Explicit System
Sequential Processing
o Many modules
One thought after
operate at the same time another. Can’t watch TV
e.g., face recognition and and read your email.
color perception
o High capacity
o Effortless
Limited by attentional and
working memory
resources.
Effortful
Life without implicit processing
Implicit Processing versus Explicit
Processing: Moral Outrage
 Sanfey et al. 2003: “The Neural Basis of Economic
Decision-Making in the Ultimatum Game” Science, 300,
1755.
 Proposer offers to split $10, and responder can either
accept or reject offer. Only one interaction.
More people will reject unfair offers (9-1, 8-2)
made by other people than offers made by
computers
 This is irrational: Should accept any offer greater
than 10-0.
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Implicit Processing versus Explicit
Processing: Moral Outrage
 Conflict between explicit processing areas of brain and
implicit processing areas of the brain:
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Implicit processing: Automatic moral outrage at the unfair
offer; subcortex lights up.
Explicit processing: Prefrontal Cortex activated to make
rational decision.
 Conflict between emotional goal (resist unfairness)
produced by implicit processing and explicit processing
goal (get as much money as possible).
 For some people, the implicit processing wins out and
they reject the unfair offers.
 For others, the explicit processing wins out and they
accept the unfair offer.
Conscientiousness: Control of implicit
processing by the Prefrontal cortex
Conscientiousness in personality psychology:
 Effortful Control: Involves explicit processing
 Delay of gratification
 Inhibition of dominant responses (overlearned or
innate); e.g., turning your head away from a light
stimulus (anti-saccade); not peeking at a present for a
child
 Pay close attention to detail (= focused attention)
 Persevere in unpleasant tasks
Conscientiousness: Control of implicit
processing by the Prefrontal cortex
Conscientiousness in personality psychology:
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Correlated ~.5 with school success
Planning for long-term goals
Dependable, responsible behavior
Linked to functioning of the Prefrontal Cortex
Inhibitory connections to Behavioral Approach System.
(BAS linked to reward-oriented behavior, impulsivity,
sensation seeking, dominance, sex, etc.)
Conscientiousness:
PFC Control
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Sub-cortical desires:
Aggression, Sexuality
Ethnocentrism
Slow developing ― Lack of conscientiousness defines
immaturity.
Conscientiousness:
The Other Inhibitory System
Development of Conscientiousness: Kochanska et al.
 Increasing coherence between 22 and 33 months of age among a variety of
tasks assessing the ability to inhibit dominant responses
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waiting for signal before eating snack,
not peeking while gift is wrapped,
not touching wrapped gift until experimenter returns.
 In general, inhibitory ability increased during this age span
 Girls > Boys
 Effortful control also predicted ability to modulate anger (tight seat belt
restraint) and ability to modulate joy (reaction to puppet show).
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This suggests effortful control is linked to control over implicit processing
stemming from affective reactions.
Kochanska, G., Murray, K.T., & Harlan, E. (2000). Effortful control in early childhood: Continuity and change, antecedents,
and implications for social development. Developmental Psychology, 36, 220–232.
Effortful Control and aggression: The general
aggression model
Anderson and Bushman, 2002
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Prepotent, evolved cues for aggression:
Implicit processing: Reflexive Aggression
 Aversive experiences produce tendencies for fight
or flight in animals and humans.
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hot temperatures
shock-induced pain
loud noises
foul odors
Crowded freeways??
Berkowitz, L. (1990). On the formation and regulation of anger and aggression: a cognitive-neoassociationistic
analysis. American Psychologist, 45, 494–503.
Evolutionary Psychology and Aggression:
Implicit processing: Reflexive Aggression
 Motives for aggression: Status, reputation, honor and sexual
jealousy as key motives for aggression.
 Adaptive problems “to which aggression might have evolved as a
solution” (p. 608):
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Co-opting resources held by others
Defending against attack
Inflicting costs on intrasexual rivals
Negotiating status and power hierarchies
Deterring rivals from future aggression
Deterring long-term mates from sexual infidelity
Reducing resources expended on unrelated children.
 Costs (e.g., possibility of retaliation) built into the module.
Buss, D. M., & Shackelford, T. K. (1997). Human aggression in evolutionary perspective. Clinical Psychology
Review, 17, 605–619.
Duntley, J. D., & Buss, D. M. (2004). The evolution of evil. In A. G. Miller (Ed.), The Social Psychology of Good
and Evil. New York: Guilford
Impulsivity as design feature of aggression as an
evolved module: Reflexive, subcortical aggression
 After being beaten, “I had stone hatred for him, and I righteously
couldn’t wait to see the look on his face when I blew him away. As
soon as he popped out of the liquor store door, I charged right up to
him, rammed the barrel in his chest, and pulled the trigger” (in
Duntley & Buss, 2005, p. xxx).
 “Effective strategies sometimes require immediate action.
Ponderous time delays and real-time extended reflection would
result in failure. Stated differently, we propose that “impulsivity” is
actually a design feature of certain adaptations that promotes their
tactical effectiveness. The fact that they appear to external
observers to be products of the lack of judicious reflection may
speak to the profound inability of human intuitions to grasp the
logic of evolved design, or to our moral judgments that classify
certain strategies as good or bad. Speedy, immediate, real-time
responses can be the product of adaptive design rather than
“mechanical failure.” ” Duntley & Buss, 2004, p. 118
Explicit processing and Aggression
 Costs and benefits calculated via explicit
prefrontal mechanisms.
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Explicit assessments of costs/benefits influence
aggression (Tedeschi & Felson, 1994)
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Aid for victim, retaliation
Likelihood of being caught (e.g., DNA
fingerprinting)
Penalties at law
 PFC is involved in active inhibition of prepotent
subcortical impulsive aggression.
PFC Inhibition of sub-cortical aggression
impulses: Damasio; Anderson et al.
 Patients with damage to the ventromedial prefrontal cortex are
driven by immediate rather than long-term rewards
 Children with damage in this area have immature, egocentric moral
reasoning and are prone to stealing and aggression. Damasio’s
“somatic marker” hypothesis proposes that the deficit stems from
the lack of inhibitory emotions normally attached to negative future
possibilities.
 Patients with prefrontal damage originating in infancy exhibited a
general lack of conscientiousness (lack of dependability, inability
to plan for the future, proneness to immediate rewards rather than
long term goals), impulsive rather than instrumental, goal-directed
aggression, and lack of guilt for transgressions against others.
Damasio, A. R. (1994/2000). Descartes’ error: Emotion, reason, and the human brain. New York: Quill
(HarperCollins).
Anderson, S. W., Bechara, A., Damasio, H., Tranel, D., & Damasio, A. R. (1999). Impairment of social and moral
behavior related to early damage in human prefrontal cortex. Nature Neuroscience 2, 1032–1037.
PFC Inhibition of sub-cortical aggression impulses: Raine
et al., 1998
 Impulsive murderers had relatively lower left and right prefrontal
functioning and higher right hemisphere sub-cortical functioning.
 Predatory murderers whose crimes involved planning and
deliberation had prefrontal functioning that was more equivalent to
comparisons, while also having excessively high right sub-cortical
activity.
 Results “support the hypothesis that emotional, unplanned impulsive
murderers are less able to regulate and control aggressive impulses
generated from sub-cortical structures due to deficient prefrontal
regulation” (p. 319).
PFC Inhibition of sub-cortical aggression impulses: Raine
et al., 1998
 Both impulsive and predatory murderers have
“excessive subcortical activity” (p. 319)—what one
might term “modular aggression.”
 Predatory murderers are better able to control
these impulses stemming from subcortical areas
because of adequate prefrontral functioning.
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Raine, A., Meloy, J. R., Buhrle, S., Stoddard, J., LaCasse, L., & Muchsbaum, M.
S. (1998). Reduced prefrontal and increased subcortical brain functioning
assessed using Positron Emission Tomography in predatory and affective
murderers. Behavioral Sciences and the Law, 16, 319–332.
Control of sexual arousal by the pfc: Beauregard
et al., 2001;
Journal of Neuroscience 21, RC 165-1-6.
 Subjects observe erotic films that brought “rapidly and
automatically a marked positive change in the
subjective emotional experience of healthy male
subjects, change correlated with significant activation
of [sub-cortical] limbic brain regions”
 Inhibitory condition: subjects instructed to voluntarily
inhibit sexual arousal to the erotic stimuli. Subjects
“were encouraged to distance themselves from these
stimuli, that is, to become a detached observer.”
Inhibition of sexual arousal by the pfc: Beauregard
et al., 2001; Journal of Neuroscience 21, RC 1651-6.
 Erotic films activated right amygdala, the hypothalamus, and the
right anterior temporal pole [Brodmann area (BA) 38]. Inhibition
resulted in no difference between erotic film and neutral film in
these areas.
 Inhibition associated with activation of right dorsolateral PFC
(superior frontal gyrus) and the right Anterior Cingulate Cortex.
Subvocal rehearsal component of verbal working memory also
involved. Sexual ideology??
Inhibition of sexual arousal by the pfc: Beauregard
et al., 2001; Journal of Neuroscience 21, RC 1651-6
 “The normal functioning of the neural network linking the right
dorsolateral PFC, right ACC, right amygdala, right anterior
temporal pole, and hypothalamus may constitute a fundamental
psychobiological mechanism through which human beings can
consciously and willfully self-regulate their emotional responses,
using various metacognitive processes. From a phylogenetic
perspective, such a circuit may implement one of the most
remarkable human faculties that has emerged in the course of
human evolution. At both an individual and a collective level, a
defect of this neural circuitry . . . may have disastrous
psychological and social consequences. Ontologically, the present
findings suggest that humans have the capacity to influence the
electrochemical dynamics of their brains, by voluntarily changing
the nature of the mind processes unfolding in the psychological
space.”
Is Conscientiousness Adaptive?
 Whether people are aggressive or act on sexual impulses comes under prefrontal
control.
 People make explicit representations of the context and costs and benefits: Will I
go to jail for being aggressive?
 People are able to control aggression or sexuality when costs outweigh benefits,
as calculated by explicit processing.
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Example: Aggression: Explicit assessments of costs/benefits influence
aggression
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Aid for victim (explicitly represented networks of allies)
Likelihood of being caught (e.g., DNA evidence)
Penalties at law
Conclusion
 Conscientiousness/Effortful Control/Active Inhibition is a
central system for inhibiting evolved tendencies and other
automatic responses in the service of long term goals (e.g.,
college education and good job) and dealing with exigencies
of the real world (e.g., calculating costs and benefits, such as
aware of social controls providing penalties for engaging in
disinhibited behavior) = Rationality.