Human Sociobiology

The application of evolution by natural selection to human behavior and cognition.

Descriptive vs. Normative (prescriptive) theories

Human sociobiology is descriptive


Heritability:

The degree to which phenotypic differences among people in one population in a particular environment can be accounted for by genotypic differences.


Genetic Determinism

 

Human behavior evolved via natural selection

and

Genes code for behavior in a rigid way, unaffected by environmental input

Examples?

Criticisms: Genetic determinism does not explain how a gene directly encodes for behavior in a developmental sense.


Cultural Determinism

The organism is a 'blank slate' upon which the environment acts to create behavioral and psychological traits

and

natural selection does not shape behavioral traits

Examples?

Criticisms:

What does culture mean?

By what process does culture cause behavior?

Cannot account for scientific evidence of heritability of behavioral traits and of the apparent adaptive significance of complex behaviors.


Interactionist Perspective

(most sociobiologists, evolutionary psychologists, and Darwinian anthropologists)

Behavior (including that of humans) is genetically heritable and is acted upon by natural selection

and

Genes and the environment interact dynamically to produce complex behavior in a developmental sense.

Goal: to determine the functional significance of particular behaviors and psychological processes.


Methods of Sociobiologists

Cross cultural:

is the trait in question uniform across many human cultures?

Comparative:

is the trait similar in closely related species?

 

Measuring reproductive success:

Is there a difference in lifetime reproductive success between individuals who possess the trait and those who do not.


Cultural Transmission

Dawkins' memes

 

a difference: can be transmitted to non-relatives within the same generation

a similarity: fitness based on ability to survive and replicate


2nd Activity

In your groups, please address the following questions regarding your assigned topic:

1: Why does this trait/practice/behavior exist?

2: Does it have any adaptive significance?

3: Design a study to test your hypothesis:

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