Ultimate and Proximate Explanations
We have already seen that there can be several levels of explanation for
behavior
Explanations answer the question “Why?”
There can be many explanations, but usually, for any explanation, we can
push back a level by asking “Why is that?”
Evolution provides the “ultimate” explanation.
There are three forms of feedback based on consequences of behavior.
Learning depends on the impact of the outcome for the person.
Social institutions (broadly defined) depend on the impact of the
outcome on the culture.
Evolution depends on the impact of the outcome on the reproduction
of the genes.
Note also that environmental factors can modify the genes themselves on
occasion.
Not shown is the effect of behavior on the rest of the environment beyond
its impact on culture, although this can be significant.
Replicators
A replicator is something that makes copies of itself, with occasional
errors.
It produces some behavior, which has consequences that affect whether or
not replication will occur.
Assume that there is some variability in the population of replicators -
Some are more likely than others to reproduce.
Genes are replicators. Are there others? Look up “memes”
Because of environmental pressures, there will be a gradual change in the
make-up of the replicators, and hence in the species
Evolution has to work with very small changes to be sufficiently precise.
Natural selection: members of a species that do not survive long enough
to reproduce to not pass on their genes
Sexual selection: when reproduction depends on sex, members that cannot
find a mate will not pass on their genes
Evolution and the Selfish Gene
The gene-based view of evolution. The gene "wants" to reproduce.
“Want”, of course, is shorthand for “will continue to affect
behavior in the species if and only if it reproduces”
The vehicle (the human) will have other desires, programmed by the genes,
which have the effect of helping the genes.
E.g., desire for fats, sexual attraction
Evolution and Adaptation
Each species has evolved to solve the problems it needs to solve.
The specific skills tell us a lot about the environment in which evolution
occurred.
Planning and problem solving are the unique skills that humans possess.
They developed to enable humans to survive in their original environment.
The key to survival was the complex structure of human society
Can evolutionary psychological hypotheses be empirically tested or falsified?
It is not hard to invent “just-so stories” (Rudyard Kipling)
A testable hypothesis must make predictions about conditions under which
a specific behavior is likely to be exhibited, and adaptive consequences
of the behavior
Example: Proffet’s theory of pregnancy sickness
Don’t people just solve problems using rationality? Wouldn’t
one domain-general rationality mechanism be more parsimonious than postulating
many domain-specific mechanisms?
The issue of “rationality” is a complex one, to be addressed
later
The modularity issue is also a matter of debate
Note that Confer et al are discussing primarily behaviors related to
sex and emotions
The area of intelligence and reasoning may be quite different
Aren’t human behaviors the result of learning and socialization, not
evolution?
The false dichotomy: Learning versus evolution
Consider language:
Clearly we must learn the grammar and vocabulary of our language
We could not do that without a built-in language module
How does evolutionary psychology take culture into account?
Cultural explanations are usually proximate explanations
These in turn have ultimate explanations
I.e., Why does a certain culture have a certain set of beliefs or attitudes?
Again, beware a false dichotomy
How do recent novel environmental phenomena affect human evolutionary psychology?
Many behaviors evolved as an adaptation to an environment that no longer
exists
This can generate behavior that is maladaptive now
Evolution is a slow process, but may show effects surprisingly quickly
Example: Left handedness
What role do genes play in the framework of evolutionary psychology?
Genetic determinism: A non-issue
The role of genes in evolutionary theories of behavior:
Using Marr’s terminology, a difference between the algorithmic and
the implementation levels
What is the practical value of evolutionary psychology?
In principle, if one understands the environmental pressures that induce
a behavior, one is better situated to modify it
What are the limitations of evolutionary psychology?
Confer et al cite some specific examples of unsolved problems
Are there any general areas of weakness?
Why are some people so antagonistic to an evolutionary psychology?
What contributions to cognitive science does evolutionary psychological
offer?
Are there issues in cognitive science that can only be addressed adequately
by taking an evolutionary approach?
Is an evolutionary perspective essential?
Can one develop a complete cognitive science without addressing the evolutionary
issues?
Debunking Myths Associated with Evolution
Complex structures can emerge gradually
E.g., the eye – any light sensitivity is useful
Evolution is not a random process: The natural selection process is far
from random
Evolution is very efficient.
Evolution is a rational decision maker:
What benefit does it offer? What is the cost? If cost exceeds benefit, get
rid of it
Given enough time, and variability, evolution can solve any problem
Orgel’s rule: “Evolution is cleverer than you are” (Leslie
Orgel, 1927-2007)
As we have seen, the “innate versus acquired” debate presumes
a false dichotomy
Innate does not mean unchangeable. In fact, evolution may facilitate change
Debunking Myths Associated with Evolutionary Psychology
The existence of innate differences among people is not a justification
for discrimination.
Beware the naturalistic fallacy - the assumption that because something
is innate it is therefore good.
Beware using an explanation an excuse (“My genes made me do it”)
Neither genetic nor environmental factors are any more or less "under
our control"