Evolutionary psychology in Russia in one picture

Evolutionary psychology in Russia in one picture

What we thought we were
What we actually are

EP is about how evolution shaped our behavior. Functionally speaking.

Pure cognitive psychology is working this way too!

Behavioral
genetics
Nature
Vs.
Nurture

So how do genetics and environment form us?

Quantitative genetics

To proceed, we will need several terms from behavioral genetics
Every phenotype (and that could be any trait) in any population has a dispersion rate
We may suggest that this dispersion consists of:
h – heritability. The difference in genes.
c – common environment. The difference in family environment.
e – individual environment + the measurement error.
Let’s take a look at how it works.

Thinking speed
Social skills
G
Ability to gain knowledge
Common sense
Creativity
G
Analytical (IQ)
Practical
Creative
Fluid
Crystallized

Suppose we have an infinite amount of identical twins couples

Let’s put them apart

Now let’s place them in different conditions
h = 0; c = ?; e = ?

Okay, what if we place them into the same conditions?
h = 0; c = 0; e = ?
CONSIDERING THAT

Now what if we take fraternal twins?
h = ?; c = const; e = const
IF SES AND THE OTHER ENVIRONMENTAL FACTORS ARE ACCOUNTED FOR

And here is how twin method works
h ( )

Biographical method and reared-aparts

By this moment we already can say much

Problems, officer?
MZ twins are supposed to be equal in many ways, but they are actually not
Genotypic-environmental covariation makes it hard to distinguish genetic influences from the environmental

Prenatal influence
Perinatal influence

Covariation

Ok, that’s good enough, but where were the genes?

3 billion nucleotides, 3 million meaningful changes, 0.4% diseases

Polygenic scores

Why does it all matter?

Every unhappy family is unhappy in its own way
Вариабельность факторов среды, влияющих на IQ в семьях с низким СЭС, примерно в 5 раз выше, чем в семьях с высоким СЭС.
Иначе говоря, семьи с низким СЭС отличаются между собой в 5 раз больше, чем семьи с высоким.

Why?
Because it is not the trait itself that is inherited, but rather the borders defining it’s maximum variation
Rats’ intelligence
Fatness

Genes make some things easier (see Rutter & autism, neurojurisprudence, gay rights),
Yet genes do not determine our destiny or what we are. They rather install the borders and filters,
In the end, it is you who determine the environment that determines how the genes determine who you are.
And that is the point of the third factor.