Transcript Chapter 18: Evolution and Human Behavior

Chapter 16: Evolution and Human
Behavior
•Minds/brains are products of
Natural Selection
•Evolutionary Psychology
•Human Universals
•Evolution of Culture
•Human Behavioral Ecology
Behaviors have evolved by the same
principles as other physical traits.
• Examples:
–
–
–
–
–
Language acquisition
Maze Rats
Pit Bulls and Mastiffs
Guinea Pigs and Grandmothers
Ants
• Large Coalitions, Complex Division of Labor, Agriculture,
Domestication, Slavery, Warfare, and Architecture
Evolutionary Psychology is the study of
Human Nature
• Species Typical Behaviors
• Innate cognitive mechanisms for making
decisions concerning specific evolutionarily
stable (ES) problems and motivate actions
based on these decisions. This involves:
1. Adaptations for perceiving, recognizing, and
making salient appropriate inputs to determine if
a ES problem exists, and assessing the costs
and benifits.
2. Choosing between possible solutions
(STRATEGIES) to problems using the gathered
inputs and filling in the blanks when information
is incomplete.
3. Attaching appropriate emotional states that
motivate actions that lead to probable solutions to
ES problems.
• The goal of this new science of the mind is to
map out all of the decision-making rules that
make up human nature.
• Deep-Blue and Casperoff
• Human Nature must be universal with low
tolerance for variability
• Shirley McLain and Sybil Theories of
Evolutionary Psychology
• Focus is on the design features of
adaptations rather then on RS
– Adaptive mismatch problem
Social contracts and the logic of detecting cheaters:
The Wason Selection Task (Leda Cosmides)
Clerical Problem
Rule: If a person has a ‘D’ rating, then his/her documents must
be marked with a ‘3’
D
F
3
5
Bartender’s Problem
Rule: If a person is drinking a beer, then he/she
must be over 21 years old’
Drinking
a beer
Drinking
a coke
25
years
old
17
years
old
• Both the Abstract and Social Contract
problems are logically identical (P, not Q)
• Significance :
– We have specialized cognitive mechanisms
(adaptations for making decisions) for policing
social contracts: CHEATER DETECTION
– If you don’t pay the cost you are not entitled to
the benefit (Reciprocal Altruism and Tit-for-Tat)
– The mind is modular:
• Functionally specific not just capacity for reasoning
• Abstract (clerical) problem not in the form of a social
contract and we don’t turn on the cheater detection
module to solve it.
Human Universals
• Color Terms
• Hopi time and 7 Words for Snow
• Incest Avoidance
– Kabbutz
– Chinese Child Brides
•
•
•
•
Expressions of Emotions
Social Structures
Near Universals
Universals: Innate Human Nature or
Universal Experience
Evolution of Culture
• Culture is about learning
– Cultural behaviors that are not innate
– Acquired in a social context
• Is culture unique to humans?
– NO
– Unique to Apes?
• NO but rare
• Social facilitation vs. Observational learning
– Monkey don’t ape
Adaptations for Observational
Learning led to:
• The ability of innovations to spread through a population
without having to evolve new adaptations.
• Individuals not having to start from scratch, they could
build on the knowledge and skill of others
• Cultural explosion
– Homo Erectus tools (choppers) were vary useful but did not
change.
– With Modern Humans there was something equivalent to
adaptive radiation with behaviors (tools, art, subsistence
practices, etc.,)
• New Data indicate that Observational learning has
special features
– Joint attention
– Functional understanding of cause and effect.
Memes and Mind Parasites
• Dawkins’ The Extended Genotype
– Meme is like Gene
– Meme is the smallest unit of memory/idea
• Memes like Genes are replicating units and
therefore follow similar patterns of replication
– Some memes die and other live (Darwin’s 1st
postulate)
– Some memes are better at reproducing than others
because they are more useful (Darwin’s 2nd postulate)
– Jump from mind to mind (Darwin’s 3rd postulate)
• Memes are units of selection and therefore can
lead to maladaptive behaviors from the
perspective of individuals.
Human Behavioral Ecology
• Humans are rational actors who act in ways to
maximize their reproductive fitness
– Adaptations lead to RS
– Phenotypic Gambit (Black Box)
• Optimization vs. Maximization
– Long term cost and benefits
– Lack: clutch size in birds
– Optimal family size (child spacing) in Chapter 19
• Optimal foraging strategies
– Game choice
– Size of hunting parties