Lecture 10 Flashcards
Define culture
The social transmission of beliefs or rules for behaviour.
For example, the acquisition of language is biological but the language you learn is cultural. Art, science, architecture, literature etc. are all examples of human culture.
Is there evidence of culture in non-humans?
There is evidence but nowhere near to the extent of humans. Some chimp populations have learnt via social transmission to fashion a stick and poke it into a termite mound in order to get food. This is also known as termite fishing. This behaviour is only present within the population. Another example; a population of chimps use leaves as a sponge in order to get more water. These differences don’t emerge because niches are different (the niches are the same most of the time), they emerge because of geographical boundaries meaning communication between the populations don’t occur. Another argument against this is that the behaviours arise because there are genetic differences, however, this isn’t possible as the behaviours have emerged too quickly. Additionally, they have replicated social learning among chimps in controlled experiments.
What is convergent evolution?
Evolution occurring separately but resulting in the same outcome among unrelated species. An example of this is dolphins and sharks.
What are the psychological processes underlying culture?
Culture is mainly based on social transmission. There are 3 types of social transmission; stimulus enhancement, emulation and imitation. Stimulus enhancement is when someone draws your attention to an object. Emulation is when you learn how to use an object by watching someone use it. Imitation is when you mimic someone’s behaviour. This is the fastest form of social transmission but also the most complex. Teaching someone something is called guided imitation. Imitation is quicker than trial and error learning and it’s useful because you benefit from your predecessors. Therefore, it makes one question why anyone would bother learning independently. Individual learners benefit because they get special treatment, we idolise those who come up with new ideas, e.g. Bill Gates.
Evolutionary psychologists are concerned with the psychology behind it but anthropologists believe it goes further than this.
Can we identify units of cultural transmission?
Culture operates as a whole rather than by specific beliefs/rules, it’s above biology and is therefore hard to explore on an individualistic level. However, Dawkins created a term for a specific unit of cultural transmission; meme.
How is cultural transmission different from biological transmission?
Cultural transmission is faster and isn’t always constant in the speed it evolves. Cultural transmission can happen vertically (through generations), horizontally (among the same generation) or obliquely (learning from unrelated older generations).
Biological transmission is much slower but is always constant in the speed it evolves. Transmission can only occur vertically.
Discuss memes from an evolutionary perspective
Memes can have fitness; some will spread through generations and some won’t. They are also subject to genetic drift; when there are no selection pressures and the success of a meme is dependent on chance but most memes become successful in this case.
How is culture adaptive?
One cultural practise is the farming of yam. However, in yam farming cultures, there are higher amounts of mosquitoes due to pools of water developing from where the yam had been removed. As a result of this cultural practise, cases of sickle cells in the population have increased because carriers are resistant to malaria thanks to the sickled cells. This shows how the culture has guided evolution to result in the adaptive advantage of malaria resistance.
Discuss cultural evolution without any fitness benefits (not adaptive)
Th evolution of teddy bears. Over time, teddy bears have become more neotenous as we have an innate preference towards baby faces and therefore buy the ones that look most like this. This effect can also be seen in dog breeds; they are slowly becoming less wolf like and more baby like. These are examples of genetic drift.
What are the three approaches about how cultural evolution happens?
Extended phenotype models; These models argue that cultergens are designed to increase elements of fitness. The fitness of the cultergen depends on whether it improves one’s genetic fitness. This is modelled on host-parasite co-evolution. One example of an extended phenotype is language; this is a meme that co-evolved with the human brain - they drove each other to evolve.
Phenogenotype co-evolution models; memes and genes are semi-independent from another. It explores conditions that maximise both genes and culture. This is a mathematical model; e.g. it’s theoretically possible that if a population had a preference for sons (culture) then a male bias sex ratio can evolve due to the coevolution of culture and biology. This also covers the malaria example. Also, modern Europeans have evolved lactose tolerance which co-evolved with increased cattle farming.
Dual inheritance; Genes and memes are completely independent, memes have their own genetic fitness. This more focuses on how the behaviours travel through generations. There are 3 mechanisms of imitation aka social learning; guided variation (learns the goal and uses trial and error to achieve this), direct bias (copies behaviour and uses trial and error to achieve the best method) and indirect bias (only copies successful behaviours).
These models can only be applied to humans as this extent of culture is uniquely human.
Discuss Henrich’s study
They provided evidence for the prestige view of cultural transmission. This view states that cultural transmission evolved because one has psychological biases from learning from those who are most likely to possess adaptive information. When this occurs over generations, cultural adaptations form. For example, they found that in the Fijian culture, those who were successful at fishing were 2 times more likely to be used as model for learning and the same was found with successful yam farmers.
Discuss Guerk’s study
They found evidence for the cultural group selection of cooperative norms. The participants played a public goods game and could choose to participate in a sanctioning or non-sanctioning society. Initially, only one third chose the sanctioning society where free-riders were punished, but by the end of the experiment, all of the participants chose to be in this group, showing how the group selected for cooperation. The fact that most did not initially pick it shows how it isn’t instinctive and rather is learnt culturally.
Discuss Insko’s study
It has been found that humans have unique cultural transmission in that we have cumulative culture. This is when we learn from previous generations and then add on new knowledge to make the process more adaptive or efficient. Insko found this with traders. They found that productivity and earnings increased as members of the group were replaced due to the intergenerational transmission causing better tactics and better division of labour. However, although this looks to support cumulative culture, there was no control group; an individual participated over time to see how their individual tactics developed. Thus, an individual may have been increasingly better at trading also.
Discuss Rogers’ theoretical model of cultural transmission
He states that cultural learning is adaptive in comparison to individual learning. This is because the cultural learners become free riders by gathering information from the individual learners. Thus, they do not have to pay any of the costs of learning and get the adaptive information without any reduction of fitness. Then, when the amount of cultural learners becomes too high, there are not enough individual learners to track environmental change. Therefore, cultural learners become less adaptive as they copy old, maladptive techniques causing them to decrease in frequency again.
