Westermarck effect

The Westermarck effect states that children who grew up together or who spent a large part of their childhood together would not find each other sexually attractive.Edvard Westermarck: The History of Human Marriage. Macmillan, London 1891; also, by the same author: Recent Theories of Exogamy. In: Sociological Review. year 26, 1934, pp. 22–44. 

The effect is named after Edvard Westermarck, a Finnish sociologist. According to Westermark, the idea is to prevent incest or inbreeding. Choosing another partner gives an advantage, so this is not a cultural phenomenon.

References

Category:Incest
Category:Human sexuality