Sexual imprinting is the process by which a young animal learns the characteristics of a desirable mate. For example, male zebra finches appear to prefer mates with the appearance of the female bird that rears them, rather than mates of their own type.
Sexual imprinting on objects other than people is the most popular theory of the development of sexual fetishism. For example, according to this theory, imprinting on shoes or boots (as with Lorenz' geese) would be the cause of shoe fetishism.
Reverse sexual imprinting is also seen: children brought up together at an early age do not find one another attractive when adult. This has been observed in the Israeli kibbutz system, and the Shim-pua marriage customs of Taiwan, as well as in biological-related families.
When this does not occur, for example where a brother and sister are brought up not knowing about one another, they may find one another highly sexually attractive when they meet as adults. This observation is consistent with the theory that reverse imprinting evolved to suppress inbreeding.