Evolutionary psychology combines evolutionary biology and cognitive psychology to study the evolution of human mind and behavior. Key ideas include: 1. Natural and sexual selection shaped the development of psychological mechanisms over generations to solve adaptive problems faced by our ancestors. 2. These mechanisms can be described as information processing systems that take in inputs and produce outputs through decision rules. 3. They are instantiated in the brain and work largely unconsciously to influence our thoughts and behavior. Understanding them provides insight into human nature.

1. Evolutionary Psychology
Dr. Atiqul Haq Mazumder
MD (Psychiatry) Part III Student
Department of Psychiatry, BSMMU
Dhaka

2. “In the distant
future . . . psychology
will be based on a new
foundation, that of the
necessary acquirement
of each mental power
and capacity by
gradation.”
--Charles Darwin, 1859

5. ‘Evolutionary psychology
is the combination of two
sciences -- evolutionary
biology and cognitive
psychology’.
Introducing Evolutionary
Psychology, Dylan Evans & Oscar
Zarate, Totem Books, New York,
2000

7. Origins of
Modern Humans
• Homo Erectus
– Migrated from Africa to Asia (1.8 MYA)

8. Increases in brain size
during evolution
ardipithecus Australopithe- homo homo Neandertal modern
cus habilis erectus human
brain size: brain size: brain size: brain brain size: brain
300 ccs 310-530 ccs 580-752 size: 1200-1450 size:
ccs 775-1225 ccs 1350
ccs ccs

9. Milestones in the Origins of
Modern Humans

10. Milestones in the Origins of
Modern Humans

11. The three theories of the
origins of complex adaptive
mechanisms

12. 1. Creationism

13. 2. Seeding theory

14. 3. Evolution by natural selection

16. Evolution Before Darwin
• Change over time in organic structures:
evolution
• Characteristics seemed to have a purpose
(porcupines, turtles, skunks)

17. Darwin’s Theory of
Natural Selection
• The explanatory challenge:
1. why change takes place
2. how new species emerge
3. what the functions are of parts

18. The answer--natural selection:
Variation, inheritance, differential
reproduction

19. The key to natural selection: Differential
reproductive success because of heritable
variants; everyone has ancestors, but not
everyone leaves descendants

20. Natural selection provided
3 key answers
• Explained change over time: descent with
modification
• Explained the apparent purposive quality
of component parts: adaptive function
• United all species into one grand tree of
descent: including humans

21. Sexual Selection

22. Intersexual Selection:
Preferential Mate Choice

23. Likelihood of Agreeing to Have Sex With Someone
You Find Attractive as a Function of Time Known
3
2
Likelihood of Intercourse
1
women
0
men
1 eve
1 year
1 hr
6 mo
3 mo
1 mo
1 day
5 years
2 years
1 wk
-1
-2
-3

24. Sexual Selection Components
• Intrasexual
Competition

26. “The core tenets of
evolutionary
psychology..”
- David M. Buss (2005)

27. Core Tenets of Evolutionary
Psychology
• 1. All behavior is a function of
psychological mechanisms + input to
those mechanisms

28. Core Tenets of Evolutionary
Psychology
• 2. All psychological mechanisms, at some
basic level, originate from evolutionary
processes

29. Core Tenets of Evolutionary
Psychology
• 3. Natural and sexual selection are the
most important evolutionary processes
responsible for creating psychological
mechanisms

30. Core Tenets of Evolutionary
Psychology
…All Species have a Nature

31. Core Tenets of Evolutionary
Psychology
• 4. Evolved psychological mechanisms can
be described as information processing
devices.
Inputs Decision Rules Outputs

32. Core Tenets of Evolutionary
Psychology
• 5. Evolved psychological mechanisms are
instantiated in the brain.

33. Core Tenets of Evolutionary
Psychology
• 6. Evolved psychological mechanisms are
functional: Designed to solve statistically
recurrent adaptive problems

34. ‘Connection do exist: our
arts, our philosophies, our
literature are the product of
human minds interacting
with one another, and the
human mind is a product of
human brain, which is
organized in part by the
human genome and has
evolved by the physical
process of evolution’.
-JOHN Brockman (2008)

35. 1975 1978

36. ‘Gene-culture coevolution’
-Edward O Wilson (1978)

37. ‘Evolutionary
psychology is…
capitalist
propaganda’
-1985

38. ‘Marxist dialectical
theory should be
applied in biology’
-1985

39. ‘Our bodies are the
vehicles of our
genes’
‘Altruism’
‘Cannibal spider’
‘Junk DNA’
‘Segregation gene’

40. -2001

41. ‘Next revolutionary
book on evolution
after Darwin’
-2006

42. 2006 Best seller

43. ‘evolution disproves the ideas behind
intelligent design’ -2006

44. standard social
science model
(SSSM)
vs.
The new science
of the mind
(1992)

45. John tooby & Leda Cosmides

46. Principle 1. The brain is a
physical system. It functions
as a computer. Its circuits
are designed to generate
behavior that is appropriate
to your environmental
circumstances.

47. Principle 2. Our neural
circuits were designed by
natural selection to solve
problems that our ancestors
faced during our species'
evolutionary history.

48. Principle 3. Consciousness is just the
tip of the iceberg; most of what goes
on in your mind is hidden from you. As
a result, your conscious experience
can mislead you into thinking that our
circuitry is simpler that it really is.
Most problems that you experience as
easy to solve are very difficult to solve
-- they require very complicated
neural circuitry.

49. Principle 4. Different neural
circuits are specialized for
solving different adaptive
problems.

50. Principle 5. Our modern
skulls house a stone age
mind.

51. ‘The Blank Slate Theory’
- John Locke ( British Philosopher, 1632-1704 )
‘Man is a blank slate on
which culture writes’
- Emile Durkheim ( French Sociologist,
1858-1917 ), 1895

52. Steven
Pinker, 2003

53. Thomas R. Insel, M.D.,
Director of the National
Institute of Mental Health
(NIMH) since 2002

54. Prairie voles
vs.
Mountain voles
-1993

55. ‘For nearly all measures
personality, heritability is
high in western society:
identical twins raised apart
are much more similar
than the fraternal twins
raised apart.’
-William R. Clark, Michael
Grunstein, 2000-11-09

56. ‘Two Identical twins raised
apart met first’
-From Blank Slate
by
Steven Pinker

57. by Martha Stout,
2005

58. Robert D. Hare,1999

59. Psychopaths, as far we know, cannot be 'cured'.
Indeed, the psychologists Marine Rice has shown
that has shown that certain harebrain ideas for
therapy, such as boosting their self esteem and
teaching them social skills, can even make more
dangerous.
-Steven Pinker, 2003

60. Jack Henry Abbott, 2005

62. ‘Cultural determinism can
be as cruel as genetic
determinism’
-Matt Ridley, 2003

63. ‘Epigenetics’
‘Neuroplasticity’
‘Malleable gene’

64. presence or absence of epigenetic factors at
target sites controls whether particular genes can
generate proteins, the workhorses of most
physiological processes.
-Douglas Steinberg, Determining Nature vs. Nurture : Molecular evidence is finally emerging to
inform the long-standing debate, Scientific American Mind, 17, 12 - 14 (2006)

66. ‘Science is discovering that
while we may have fixed set of
genes in Chromosomes, which
of those Genes is active has
great deal to do which our
subjective experiences, and how
we process them’
-Dawson Church, 2009

67. Josephine Tesauro, left, active and healthy at 92, is part of a study
trying to determine why some people age better than others, even
when they are closely related.
Live Long? Die Young? Answer Isn’t Just in Genes, GINA KOLATA, The NewYork Times,
August 31, 2006, Online link: http://www.nytimes.com/2006/08/31/health/31age.html

68. With no more than a change in diet, laboratory agouti mice (left) were
prompted to give birth to young (right) that differed markedly in
appearance and disease susceptibility.
DNA Is Not Destiny, The new science of epigenetics rewrites the rules of disease,
heredity, and identity; Ethan Watters, Discover Magazine, Nov. 2006 issue, Online link:
http://discovermagazine.com/2006/nov/cover/?searchterm=Randy%20Jirtle

69. Nature vs. Nurture No
Nature via nurture Yes
We are the minders of our
genes
Evolutionary psychology
describes what human nature
is like - it does not prescribe
what humans should do'।

70. Thank you!