Psych 1XX3 – Lecture 2 – Evolution – January 22, 2013
**Heritable variants lead to differential reproductive success.
Outcome variance can drive different solutions to the same problems.
o Low variance – most respond close to the mean
o High Variance – more spread data
o Inputs Decisions Rules Outputs
o 1. Behavior = psychological mechanisms + input
o 2. Evolved psychological mechanism coded in brain
o 3. Evolved psychological mechanisms can be described as information processing
devices. i.e. how can someone maximize their reproductive success
Genetic resemblance is something people can identify.
1. Genes and family resemblances
o baby can look more like one parent than the other
o more comments about similar characteristics and father; baby looks more like the
2. Thought experiment: Looking for Love…
o What do women look for; what do men look for?
o Women: loyal, honest, “different”, stability, responsibility, maturity
o Men: body type, no genetic relatedness, physical attractiveness
3. Romance in the friend zone?
o Can men and women actually just be friends?
o 1. Are you attracted to your friend?
Men tended to be attracted to their friends, women far less so.
o 2. Is your friend attracted to you?
Men assumed that their friend is attracted to them.
If the guy was attracted to the girl, he assumed girl was attracted to him.
3. Would you date your friend?
Men said yes.
To men this friendship is a potential partner, and women believed they
were JUST friends.
Different adaptive Problems
o 1. Metabolic demands of reproduction.
Much greater for woman, than man.
o 2. Potential differences in parental demand
woman gives birth – man may or may not be there
o 3. Genetic cuckoldry
women are 100% sure the baby is hers (unless IVF), whereas men cannot
be 100% sure that the baby is his. i.e. he might