Olfactory sexual inhibition and the westermarck effect

Abstract

The Westermarck effect (sexual inhibition among individuals raised together) is argued to be mediated olfactorily. Various animals, including humans, distinguish among individuals by scent (significantly determined by MHC genotype), and some avoid cosocialized associates on this basis. Possible models of olfactory mechanisms in humans are evaluated. Evidence suggests aversions develop during an early sensitizing period, attach to persons as much as to their scents, and are more powerful among females than among males. Adult to child aversions may develop similarly, but more likely result from stimulus generalization. This hypothesis accords with current evidence and yields testable predictions (e.g., anosmia will prevent inhibition) that, should they be supported, will conclusively ground the Westermarck effect in a biological mechanism.

Incest Avoidance, the Incest Taboo, and Social Cohesion: Revisiting Westermarck and the Case of the Israeli Kibbutzim

“…Despite sporadic challenges, mainly from anthropologists (e.g., Graber 1984;Kopytoff 1984;Leavitt 1989Leavitt , 1990Harris 1991), the bulk of scholarly work on incest during the past two decades adopts Westermarck's aversion hypothesis (e.g., Erickson 1989Erickson , 1993Bvec andSilverman 1993, 2000;Wolf 1993Wolf , 1995Wolf , 2005bWilliams and Finkelhor 1995;Lieberman and Symons 1998;Sesardic 1998Sesardic , 2005Schneider and Hendrix 2000;Fessler and Navarrete 2004). While some of these writers are more careful and talk about disinterest (Uhlmann 1992) or "a barrier specific to potentially reproductive acts rather than a general suppressor of sexual interest" (Bvec and Silverman 1993, p. 159), most align with Westermarck and use the term aversion when discussing the results of early association.…”

“…In the past few decades a consensus seems to be forming over one of the major questions that has fueled this debate: What is the major cause for incest avoidance? Increasingly, scholars maintain that Edward Westermarck was right when he suggested in 1889 that early childhood association leads to sexual aversion, which is in turn the reason for incest avoidance (e.g., Erickson 1989Erickson , 1993Lieberman and Symons 1998;Schneider and Hendrix 2000;Wolf 2005b). Many of these scholars also support Westermarck's second proposition, that this aversion is the historical source of the incest taboo (e.g., Wolf 1993;Fessler and Navarrete 2004;Bateson 2005;Sesardic 2005).…”

Naturalising Ethics: The Implications of Darwinism for the Study of Moral Philosophy

“…This was how natural selection solved the problem of inbreeding with relatives: if we have grown up with someone it is likely that they are closely related. So far, in relation to the broad set of ideas that comprise the Westermarck effect, work has tended to suggest: (a) inbreeding does cause a depression in fitness (Bittles and Makov 1988;Bittles 1995Bittles , 2004; (b) early co socialisation tends to inhibit sexual desire (Bevc and Silverman 1993;Wolf 1993;Sherper 1971) (c) other primates have mechanism to avoid inbreeding (Pusey 2004); (d) the proximate mechanism that leads co-socialised humans to avoid mating may be olfactory or even explicable in Freudian terms Spain 1991;Schneider and Hendrix 2000); (e) the moral condemnation of incest varies according to the experience of the individual expressing such views (Lieberman et al 2003;Fessler and Navarrete 2004).…”

Sensual Attachment and Incest Avoidance in Human Evolution and Child Development

“…Thus the mechanism can account for how early close association promotes sexual avoidance of step‐parents and step‐siblings as well as close biological relatives. In human beings, the mechanism probably depends on sex hormone‐related scents produced by glands in the axilla (M.A. Schneider & Hendrix 2000).…”