BEHAVIORAL GENETICS AND EVOLUTIONARY PSYCHOLOGY

Genetics

We have 23 pairs of chromosomes

Half from genetic mother, half from genetic father

What do genes do?

Function of genes

Chromosome is made of genes

Each gene codes for a protein

Genes can be turned “on” or “off”

How similar are we?

Humans are 99.9% similar

Humans and Chimps are 96% similar

Humans and bananas are 50% similar!

Twin Studies

Twin studies examine similarities and differences between identical and fraternal twins

Identical twins are far more similar than fraternal

Separated at Birth?

Famous example: The Jim Twins

Same name, same wives, same pets, same hobbies, same habits

Could this just be coincidence?

Adoption Studies

Another fantastic way to examine the impact of genes and environment.

Personalities- largely genetic

Then why are siblings so different?

Temperament

Difficult 10%

Easy 40%

Slow to warm up 15%

Identical twins have more similar temperaments

Gene Environment Interactions Environment triggers gene activity

Gene activity influences the environment

Temperament as an example?

Choosing environments

Evolutionary Psychology

What makes us similar?

What is natural selection?

Not just “survival of the fittest”

Grandpa Simpson: I used to be with it, but then they changed what it was. Now what I'm with isn't it, and what's it seems weird and scary to me. It'll happen to you...

Selection

Environmental Pressures

Sexual Pressures

Domestication and Breeding

Why has evolution made us fat?

Gender Differences

It’s all about the sex!

Men are more likely to be sexually liberal

Women are more likely to be sexually conservative