Evolution and Behaviour Flashcards
What is the evolutionary argument and human behaviour
[Theory/hormone we release/natural selection]
As we evolve and reproduce new generations, it is due to natural selection (stronger one lives, weak one dies)
The evolutionary theory states it is more desirable to find a mate who is healthy and strong so they can produce offsprings that are better suited to the environment.
= may influence sexual selection
- An evolutionary argument that can explain human mating behaviour, is sexual selection.
- Evolution is the change over time in living organisms of heritable characteristics of a species.
- The theory of evolution states that by natural selection, organisms that adapt better to environmental changes are more likely to survive, reproduce, and thus pass on their genes.
- Sexual selection, a particular aspect of natural selection, states that in order to produce and protect the most healthy offspring, the perfect mating partner is found.
- Because the evolutionary argument states this, the way humans find mating partners must be beneficial to human survival and reproduction, and thus an adaptive behaviour.
Aim of Ronay and von Hippel
to determine if men would take greater risks in the presence of an attractive female and if testosterone played a role in this behaviour
Procedure of Ronay and von Hippel
- Convenience sample 96 young adult Australian male skateboarders with a mean age of 21.58
- Assigned to either male-researcher condition or female-researcher condition.
- Skateboarders were asked to do one “easy trick” and one difficult trick which they could successfully complete approximately 50% of the time. They were asked to do each trick 10 times.
- Asked to make 10 more attempts of each trick but in either condition
- The attractiveness of the researcher was established by having 20 male rate photos of potential female experimenters.
- High levels of aborted attempts would be seen as an indicator of low-risk taking.
- Saliva samples were used to measure for testosterone after
- Heart rate throughout
Findings of Ronay and von Hippel
Took greater risks on difficult tricks in the presence of the female researchers
Testosterone levels were higher in the presence of female researcher
No sig difference heart rate
Conclusion of Ronay and von Hippel
According to evolutionary theory, this makes sense. The increased risk-taking is a sign to potential mates that the male is healthy, strong and dominant - that is, would be able to intimidate any potential rival.
What is the pheromone and behaviour involved in the Wedekind study (1995)
[Theory/hormone we release/natural selection]
There are theories that one of the potential role of pheromones in human behaviour is responsible for mate selection.
MHC - group of genes that play an important role in the immune system
The more diverse the set of genes for the MHC is in the parent, the stronger it is in their offspring, which makes it very favourable to choose a mate with a different MHC combination for natural selection.
Aim of Wedekind
to determine whether one’s MHC would affect mate choice.
Method of Wedekind
49 female and 44 male students from a University of Bern. There was wide variance of MHC. It was noted if the women were taking oral contraceptives. The students from different courses probably did not know each other
men wears a T-shirt for two nights and to keep the T-shirt in an open plastic bag during the day. They were asked to refrain from actions and products that could affect their natural scent (tobacco/perfume etc)
women then rank the smell of 7 t-shirts. The women were tested in the second week after the beginning of menstruation, as women appear to be most odour-sensitive at this time. They prepared themselves for the experiment by using a nose spray for the 14 days before the experiment to support regeneration of the nasal mucous membrane if necessary – as well as a preventive measure against colds or flu.
3/7 boxes contained T-shirts from men with MHC similar; three contained T-shirts from MHC dissimilar men;
1/7 contained an unworn T-shirt as a control.
Alone, they scored the odours of the t-shirt for intensity (0-10) and for pleasantness and sexiness (range 0 -10, 5 = neutral).
Findings of Wedekind
Women scored male body odours as more pleasant when they differed from their own MHC than when they were more similar. This difference in odour assessment was reversed when the women rating the odours were taking oral contraceptives.
Conclusion of Wedekind
This suggests that the MHC may influence human mate choice.
