Your analysis is correct, and there is evidence that older siblings use different cues to infer kinship. This paper gives a great overview of the issue, and argues that one cue older siblings use is seeing their mother closely associated with and taking care of another young child.
The paper also provides a really interesting kind of test case for what they refer to in other work and a little bit here as an internal regulatory variable--the kinship estimator, which is a value stored internally that feeds into multiple different processes, in this case altruism and incest avoidance.
They show how one might test and provide evidence for such a mental entity that is not itself directly observable. I just looked at the article you referenced and it's about the effects of MPA, not the Westermarck effect, and so actually provides somewhat of an answer to your question. It's also thought that there may be cues derived from MHC detected through scent as well--This is discussed in the paper I linked to.
To answer your last question, I don't think there is data on rates of incest by sibling age difference probably because it is extremely rare , but I know there is some evidence that the strength of the disgust reaction to thinking of incest with an opposite sex sibling is calibrated by exposure to kinship cues sorry I don't have a cite offhand, but you might try checking out Debra Lieberman's work.
Actually, the Lieberman, Cosmides, and Tooby paper that you linked to discusses a the strength of disgust reaction, b the strength of altruistic impulses, and c moral opposition to 3rd-party incest.
The findings were, basically, that the Westermarck hypothesis only explains any variance when MPA is absent. Jesse Bering cites several studies that seem to contradict the standard view of the Westermarck effect as an innate learning process; instead, it may be a cultural phenomenon.
People seem to have sexual preferences toward faces that resemble their parents' or their own. If correct, this would suggest that Freud's idea of the Oedipus complex had some merit to it.
Westermarck effect The Westermarck effect , or reverse sexual imprinting , is a hypothetical psychological effect through which people who live in close domestic proximity during the first few years of their lives become desensitized to sexual attraction. Contrasting Westermarck and Freud Freud argued that as children, members of the same family naturally lust for one another See Oedipus complex , making it necessary for societies to create incest taboos ,  but Westermarck argued the reverse, that the taboos themselves arise naturally as products of innate attitudes.
Steven Pinker wrote on the subject: The idea that boys want to sleep with their mothers strikes most men as the silliest thing they have ever heard. Obviously, it did not seem so to Freud, who wrote that as a boy he once had an erotic reaction to watching his mother dressing. But Freud had a wet-nurse , and may not have experienced the early intimacy that would have tipped off his perceptual system that Mrs. Freud was his mother.
The Westermarck theory has out-Freuded Freud. The Westermarck theory has out-Freuded Freud. Some sociologists and anthropologists have criticized the validity of research presented in support of the Westermarck effect and the contention that it serves as an ultimate demonstration for the viability of natural selection theory in explaining human behaviour.
For example, a study by Eran Shor and Dalit Simchai demonstrated that although most peers who grew up closely together in the Israeli kibbutzim did not marry one another, they did report substantial attraction to co-reared peers. The authors conclude that the case of the kibbutzim actually provides little support for the Westermarck Effect and that childhood proximity cannot in itself produce sexual avoidance without the existence of social pressures and norms.
From Wikipedia, the free encyclopedia. This article includes a list of references , but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations. November Learn how and when to remove this template message. Revisiting Westermarck and the Case of the Israeli Kibbutzim". American Journal of Sociology.
Accidental incest Avunculate marriage Child incestuous abuse Consanguine marriage Cousin marriage notable cases in the Middle East Covert incest Inbreeding Incest between twins Motherfucker Parallel and cross cousins Snokhachestvo Sibling incest.
The Westermarck effect, or reverse sexual imprinting, is a hypothetical psychological effect through which people who live in close domestic proximity during the first few years of .
I was thinking about the Westermarck effect, and it struck me that if it's an explanation for incest-avoidance between siblings, it could not.
Moral relativism is the view that moral judgments are true or false only relative to some particular westermarck effect criticism standpoint (for instance, that of a culture or. Marcinkowska, Fhionna R. Effects of brother relationship characteristics (subjects with one brother) The critical analyses in this section were exploratory, and checked whether additional cues for sibling detection could be identified.
PDF | On Sep 1, , Jan Antfolk and others published Westermarck Effect. Westermarck effect The Westermarck effect, or reverse sexual imprinting, is a hypothetical psychological effect through which people who live in close domestic proximity during the first few years of their lives become desensitized to sexual attraction.