Evolutionary Psychology

1
Evolutionary Psychology

• Stephanie Taylor
• Evolution
• April 28, 2004

2
What is Evolutionary Psychology?

• Approach to psychology, using principles of
  evolutionary biology
• Mind is a set of processing machines
• natural selection adaptation problems
• Focuses on evolved properties of nervous system

3
Background Info.

• Darwinian concepts ? neobehaviorism
• William James focused on instincts.
• -neural circuits
• Weisman showed that natural selection was not a
  solution to the bettering of society

4
5 Basic Principles

• 1. The brain is a physical system that functions
  as a computer
• 2. Our neural circuits were designed by natural
  selection to solve problems faced by our
  ancestors
• 3. Most of what goes on in our minds is
  unconscious
• 4. Different brain circuits are designed to solve
  different adaptive problems
• 5. Inside our modern skulls lies a stone-age mind

5
A Different Approach

• Darwin -phylogenetic approach to determine why
  differences exist among species
• EPs -adaptationist approach
• - adaptive designs that look at
  niche-differentiated mental abilities

6
Design Evidence

• Determine various adaptive problems that a
  species encountered
• What type of mechanism or machine would be able
  to solve this problem given the conditions of
  that time?

7
Nature or nurture???

• EPs say BOTH!!!
• A genotype is that product of both genes and
  environment
• Natural selection designed developmental
  mechanisms

8
Inclusive Fitness

• An individual not only passes on their own genes,
  but the genes of their ancestors as well
• Explains why we look after people that are
  genetically related to us, in addition to
  ourselves

9
Men are from Mars, Women are from Venus?

• Difference in gender behaviors reflects different
  contributions to reproduction
• Mens vs Womens designed roles
• The best way for a male to maximize fitness is to
  create a diverse mating population

10
Polygyny

• A study of 853 different cultural societies
  showed that 83 of men are polygynous
• In the U.S. there are 25,000-30,000 polygynous
  marriages
• A study of 437 men revealed that they had 2
  families, neither of which knew about the other

11
Evolutionary or a character flaw?

• Human genitalia is between that or gorilla and
  chimps in size, thus humans are expected to be
  intermediate in polygyny and promiscuity as well

12
Child Abuse

• Infanticide in primates
• Stepparents are more likely to abuse a child that
  biological parents
• Abuse by biological parents
• -demanding investments
• -threat to reproduction

13
Racism, Prejudice, and Discrimination

• May have rooted in the immune system
• Ancestors had to compete for resources to benefit
  family and tribe
• Any outsider was a threat
• More competition for resources

14
Prejudice, contd

• Prejudice and bigotry, then, developed due to
  survival of self and bettering of the particular
  society
• In modern society, EPs view discrimination and
  prejudice with respect to resources as well
• - not so much emphasis on skin color, as we
  commonly think of

15
Homosexuality

• E.O Wilson
• -homosexual individuals helped family members
  reproduce more successfully
• Genes for homosexuality passed on through
  relatives
• Does not have an adaptive value
• Not a product of natural selection

16
More Thoughts on Homosexuality

• Is a variation of behavior that demonstrates
  fitness enhancing qualities
• Same sex alliance did contribute to survival
• -conflict resolution

17
Summary/Conclusions

• Some actions deemed as immoral actually make
  sense
• Helps to gain understanding of human nature
• Provides missing pieces of puzzle left by
  individual disciplines of evolutionary biology
  and psychology

18
References

• Cosmides, L., Tooby, J. Evolutionary Psychology
  A Primer. Center for Evolutionary Psychology,
  University of Santa Barbara. httP//www.psych.ucsb
  .edu/research/cep/primer.html (April 14, 2004)
• Crawford, C., Krebs, D. Handbook of Evolutionary
  Psychology. New Jersey Lawrence Erlbaum
  Associates.1998.
• Hagen, E. Evolutionary Psychology FAQ.
  Institute for Theoretical Biology.
  http//www.anh.ucsb.edu/projects/human/epfaq.ep.ht
  ml (April 15, 2004)
• Miele, F. The Immoral Animal. Skeptic. (4)1.
  1996. pp. 42-49. http//www.sketic.com/04.1.miele
  -immoral.html (April 14, 2004)
• Spriggs, W. Evolutionary Psychology and the
  Origins of Racism, Prejudice, Bigotry, and
  Discrimination An Updated View. Evolutions
  Voyage. http//www.evoyage.com/BillsEssays/Racism.
  htm (April 16, 2004)

19

• The End