evolutionary explanations for behavior

Question 1

evolutionary expanations for behavior intro

Answer 1

Darwin’s theory of natural selection explains how species acquire adaptive characteristics to survive in an ever-changing environment. According to the theory of natural selection, those members of a species who have characteristics which are better suited to the environment will be more likely to breed, and thus to pass on these traits.

Evolutionary psychology is grounded in the theory that as genes mutate, those that are advantageous are passed down through a process of natural selection. Evolutionary psychologists attempt to explain how certain human behaviours are the result of the development of our species over time. It is important to remember that natural selection cannot select for a behaviour; it can only select for the genes that may produce behaviour.

Idea that u are more likely to be afraid of things that may have hurt u in the past
Becomes a problem if your level of fear is disproportionate to the danger e.g being so afraid of a dog that you cant even approach it, even tho it cant kill u ?
maladaptive, exagerated response

cant show people psychological behaviour changed in past
cant be sure its due to environment, other factors
psychological
evolution: gradual change to adapt to environment, those better suited produce more offspring and pass genes

phobias - preparedeness, easy to learn phobias for things that threatened ancestors in past e.g snake rather than car
classical conditioning - learn to associate one thing w another

evolutionary preparedness - learned to fear anything that threatened our surivival faster than other things - learn quick without experience, born ready to learn
increase survival for ancestors
if they didnt fear those things they die more easily
extinction - when u stop associating fear, no longer classically conditioned
harder to forget association between snakes, easier to forget flowers

Question 2

skre et al

Answer 2

Aim- to investigate the genetic and environmental contribution to common phobic fears

Method
61 twin pairs used where one twin had received treatment for an anxiety or disorder at some point in their life.
MZ or DZ was determined using questionnaires and blood samples
Comon phobic fears determined using questionnaire
Agoraphobic (anxiety of places that make u feel trapped and helpless)
Social
Animal
nature/situational
Blood injection injury
Asked to rate fear from 1 to 5 for diff objects

Self-reported common phobic fear was studied in a treatment sample of 23
monozygotic and 38 same-sex dizygotic twin pairs

RESULTS
Heritability of .47 was observed for common phobic fear of small animals and social fear
heritability of .30 in common agoraphobic fear
For common fear of nature phenomena and situational fear, the heritability was 0
CONCLUSION
Mixed conclusions
common nature and situational fears were solely caused by environmental factors → in support of learning theory
results for animal, social, and other common phobic fear are in support
of an integrative theory of biological preparedness, learning history, and a cognitive style of fearful expectation.
common animal fear and social fear had moderately high heritability, whereas common agoraphobic fear had somewhat lower heritability. For common social fear there were, however, indications that non-additive genetic effects may have an influence. Finally, common fear in relation to nature forces and other situations seem to be influenced only by environmental factors.