The Biological Perspective

1
The Biological Perspective

• Evolutionary Psychology

2
The Theory of Evolution

• Perhaps the single most important idea ever
  conceived

3
What is evolution?

• Evolutionary theory consists of several simple
  assumptions
• Within a species there is heritable variability.
• Some variations result in more offspring's, who
  will themselves possess these beneficial
  differences.

4
Standard explanations for human behaviour

• Animals are rigidly controlled by their biology,
  human behaviour determined by culture and
  learning.
• Learning is a general purpose process used in all
  domains of knowledge

5
Evolutionary Psychology

• Big Ideas
• Evolutionary Biology Cognitive Psychology
• Goal is to understand the human mind/brain from
  an evolutionary perspective
• The design of the mind must have been shaped by
  natural selection (including sexual selection a
  special case of natural selection. Defined as
  an organism's ability to obtain and successfully
  copulate with a mate. )
• human minds, behavior, artifacts and culture are
  all biological phenomena

6
Evolutionary Psychology

• Big Ideas
• Our mental lives and behavior reflect the
  evolutionary history of our species, particularly
  the adaptive problems that had to be solved ? our
  modern skulls house stone age minds designed to
  increase evolutionary fitness
• different neural circuits are specialized for
  solving problems e.g. vision love
• we accomplish difficult tasks easily and
  unconsciously

7
Our Evolutionary Environment

• The EEA probably consisted of
• Hunter/gather/scavenging subsistence
• Nomadic or semi-nomadic
• Low population density
• Small kin-based groupings
• Simple technology
• High infant mortality and low life expectancy
• Vulnerability (e.g. predators, disease)
• Few lifestyle options

8
Adaptive Problems

• Our minds were designed by natural to solve
  adaptive problems faced by our hunter-gatherer
  ancestors.
• avoiding predators
• eating the right food
• attracting mates
• forming alliances
• reading others peoples minds
• All of these things are crucial for
• passing on your genes. We
• therefore expect selection to
• have designed mental mechanisms to
• solve these problems.

9
Are all behaviours adaptive?

• Evolutionary psychologists habitually look first
  to adaptive explanations.
• It is not always possible to explain behaviours
  as adaptive and we must take into account the
  following
• In some cases the environment may change more
  rapidly than the organism can evolve.
• An adaptation is not always adaptive in every
  circumstance.

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Insights From Evolutionary Psychology

• Our mind consists of a set of domain specific
  information processing modules e.g. language,
  theory of mind, perception.
• Food preferences Strong desire for fat was once
  very adaptive, no longer so.
• (Speculation An environment in which food is
  only periodically available e.g. by dieting -
  means it is adaptive to switch on more fat
  storage)

11
Insights From Evolutionary Psychology

• Perception Our color vision is adapted to seeing
  ripe/unripe fruits against background foliage
• Mood Evolution has no interest in maximizing
  happiness!
• Anxiety Makes us cautious about actions we
  should be cautious about.
• Sadness Makes us withdraw from situations in
  which we might suffer further loss.

12
Insights From Evolutionary Psychology

• Anger and kindness Produce the effective tit for
  tat style of negotiation
• Phobias fear of snakes vs. fear of guns
• Depression Should withdraw from a major life
  endeavor and start a new one?
• Men and womens mate preferences and sexual
  strategies differ.

13
Male and Female Sexuality

• innate differences ? gender not a social or a
  cultural construct
• monogamy not the natural state of affairs,
  multiple sex partners, polygamy and serial
  monogamy would serve a range of evolutionary
  purposes
• differences between males and females mate
  selection involves inherent conflict

14
Male Sexuality

• large number of mates desire
• power and status a means of attracting them
• often applies the Madonna-whore double
  standard
• interest declines after 4-5 years
• extreme jealously evoked by sexual
• infidelity

15
Female Sexuality

• far more discriminating in mate selection which
  is based on the quality of the genes and
  potential to invest in child rearing
• infidelity may result if the mate can not provide
  support
• extreme jealously evoked by emotional infidelity
  as it threatens a lose of material support

16
We are not slaves to our genes.