Cultural evolution continues throughout life says new research theory

The number of learning opportunities a person is exposed to is of great importance to that individual's cultural evolution during his/her lifetime, according to researchers at Stockholm University.

With the aid of mathematical models, these scientists show that there are differences between cultural and biological evolution. These findings were recently published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

“Since there are many similarities between biological evolution and cultural changes, the research community has often suggested that the theory of biological evolution can also be applied in relatively unaltered form as a model for cultural evolution. Using these methods, genes are replaced by so-called memes, which are small cultural elements, and then the same methods are used as in biological evolutionary theory,” says Magnus Enquist, professor and director of the Center for the Study of Cultural Evolution at Stockholm University.

The current article uses mathematical models to show that there is a crucial and often neglected difference between biological and cultural evolution.

“In connection with fertilization, all genes are transferred to the new individual at one and the same time. In contrast, the individual acquires culture successively and throughout life, which can lead to dramatic consequences and create widely divergent conditions for various individuals in a way that biological evolution does not,” says Magnus Enquist.

With many learning opportunities, the individual's opportunities to actively choose among different cultural variants are of great importance to his/her development. Earlier choices form a foundation for choices to come, and clear differences can be discerned between the cultural evolution of different individuals that can be tied to how often they are exposed to cultural influences.

The factor that is of the greatest importance in the development of theory is the so-called frequency of exposure, which shows that the fewer occasions for exposure an individual encounters, the weaker that individual's evolution is. In such cases the capacity for dissemination is what determines evolution, in the same was as with biological evolution.

“One finding that surprised us was that who the individual inherited the culture from did not have any direct impact on the results. In other words, it made no difference whether the culture was passed on by the parents, from peers, or from the collective. The very fact that the cultural heritage is not tied to the parents, which has been regarded as the most important difference between biological and cultural evolution, also strengthens our theory.”

Another important conclusion in the article is that there is no simple principle that can predict all cultural evolution in the same way that biological fitness predicts biological evolution. However, a simple variable was able to predict the prevailing cultural variant when the number of learning opportunities was great.

“Hopes of being able to create a theory of cultural evolution or change have often been dashed. With the ideas presented in the article, which are less tied to biological evolutionary thinking and allow cultural evolution to have its own peculiar characteristics, we have a greater chance to succeed in fashioning such a theory,” says Magnus Enquist.

The article can be read at:
http://www.pnas.org/content/early/2009/07/28/0903180106.full.pdf+html?sid=6313447a-8944-4ee2-a02f-0b13b3b71e7c
Further information
Magnus Enquist, professor and director of the Center for the Study of Cultural Evolution, Department of Zoology, Stockholm University. Cell phone: +46 (0)73-707 87 59. E-mail: magnus.enquist@intercult.su.se

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