Download Evolution

EVOLUTION
2.2 Genetics and behaviour
Evolution
Charles Darwin’s theory of evolution
• The environment challenges the individual
• Which leads to that those who adapt best to
the environments challenges will have a
greater chance of surviving, giving offspring,
and so pass on their genes to next
generation.
The theory of
natural selection
Charles Robert Darwin
12 February 1809 – 19 April 1882
Survival of the fittest
One develop
characteristics that are
suitable for the
environment - adaption
DARWIN AWARDS
FAVORITE QUOTE!
"Just think how stupid
the average person is,
and then realize that
half of them
are even stupider!"
--George Carlin
Darwin laid
the
foundation for
psychologist
and biologist
to study
animals – to
get more
insight about
humans
Examples of what one can study using
animals (and mostly primates)
1
• Language
2
3
•Mate selection
• Facial expressions
Evolutionary psychology
• Genes mutate,
those that are
advantageous are
passed down
through a process
of natural selection
• They try to explain
how we have
developed over
time and why
NATURAL SELECTION
CANNOT SELECT A
BEHAVIOUR!
CAN ONLY SELECT
MECHANISMS THAT
PRODUCE BEHAVIOUR
One example of
evolutionary research
The study of emtions: Fessler
(2006) did research on disgust
Study on disgust
• Fessler argued that disgust allowed our
ancestors to survive long enough to produce
offspring.
Fessler study on disgust
• Fessler Investigated the nausea experienced
by women beginning of their pregnancy
• During this period an infusion of hormones
lowers the expectant mother’s immune
system so as not to fight the new foreign
genetic material in her womb.
• His theory: maybe the nausea response helps
to compensate for the suppressed immune
system
Method
• 496 pregnant women,
• Let them consider 32 potentially stomachturning scenarios
• Let them rank how disgusting they were
• Example: sticking a fish hook through their
finger
Disgust
• Another study by Curtis
et al. (2004) who
carried out an online
test to test whether
there are patterns in
people’s disgust
responses. Try it now:
• http://www.bbc.co.uk/
science/humanbody/m
ind/surveys/disgust
Results of the studies
Fessler
• Women scored higher in the beginning of their pregnancy
and the ones having morning sickness scored high on the
ones involving food.
• Natural selection may have helped compensate for the
increased susceptibility to disease during this risky period
in pregnancy, by increasing the urge to picky about food
Curtis
• Disgust was stronger for those images which threaten our
immune system – women showed higher which supports
the first study as well
• Disgust decreased with age
Evolutionary psychology
• Weaknesses:
• They see what they want to see –
confirmation bias. Difficult to test the
theories
• Little know how it really was back in time –
hypothetical
• Underestimate the role of culture in shaping
behaviour
Article for next class
• Read the article Eugenics revisited
1. Come prepared to discuss the article on
Wednesday
2. come up with at least two discussion
questions for the class to discuss