In the last post on Thinking about Incest, I left off by introducing attachment as a possible mechanism for the Westermarck Effect. While so far as I know, Westermarck did not discuss attachment under that heading, in Chapter 17 (“The Killing of Parents, Sick Persons, Children, Feticide”) of volume 1 of The Origin and the Development of the Moral Ideas (1906), Westermarck says several interesting things about parental love, and the relationship between habit, custom, and morality. In discussing infanticide amongst “uncivilized races” and “the lower savages”—the language here a reminder of Westermarck’s immersion in the academic culture of his day—(p. 402), he says
Considering further that the custom of infanticide, being opposed to the instinct of parental love, presupposes a certain amount of reasoning or forethought, it seems probably that where it occurs, it is not a survival of earliest savagery, but has grown up under specific conditions in later stages of development. (pp.402-403).
So here it is clear that Westermarck thinks there is an “instinct of parental love”. Slightly earlier, Westermarck talks of its development, at least in fathers, over time, something that explains why infanticide, when it occurs, occurs earlier, rather than later, in the life of the infant, “when the father’s affection for it [the infant] is as yet only dawning” (p.402). Although this is characterized by Westermarck as an instinct, note that it requires a certain amount or perhaps kind of experience in order for that instinct to become manifest, and strong enough to inhibit whatever infanticidal tendencies there are in the species. On the dawning of “father’s affection”, Westermarck continues by saying:
Even where, at first, infanticide was an exception, practiced by a few members of the tribe, any interference from the side of the community may have be prevented by the notion that a person possesses proprietary rights over his offspring; and, once become habitual, infanticide easily grew into a regular custom. In cases where it was found useful to the tribe, it would be enforced as a public duty and even where there no longer was any need for it, owing to changed conditions of life, the force of habit might still keep the old custom alive (p.402)
Leading in to this discussion, Westermarck says that the advantages, real or perceived, from infanticide “have been sufficiently great to silence the voice of parental love, which, as will be seen, is to be found even in the bosom of a savage father” (p.401). That “voice”, we have just seen, is regarded by Westermarck as an instinct that requires certain kinds or levels of experience to be triggered effectively, but the tendency to infanticide itself is viewed by Westermarck as the result of a custom, one that is more rational and calculative. It’s interesting that he doesn’t seem to characterize this tendency as the result of an instinct, a view that has been defended in the contemporary sociobiological literature by Sarah Hrdy (initially with respect to langurs) and Martin Daley and Margo Wilson.
Slightly later on, in cashing his promissory note here, and with a series of illustrations from “savages” of which I provide just one, Westermarck says
That the custom of infanticide is generally restricted to the destruction of new-born babies also appears from various statements as to the parental love of those peoples who are addicted to this practice … Among the Indians of the pampas and other Indians of that neighbourhood, who abandon deformed or sickly-looking children to the wild dogs and birds of prey, an infant becomes, from the moment it is considered worthy to live, ‘the object of the whole love of its parents, who, if necessary, will submit themselves to the greatest privations to satisfy its least wants or exactions’ [here he quotes Auguste Guinnard, p.144, likely the 1871 edition of Three years’ slavery among the Patagonians: an account of his captivity.] (pp.404-405)
Much of interest in this in general, and for thinking about the Westermarck Effect in particular: customs of infanticidal death directed at “deformed or sickly-looking children”, the idea of competing tendencies—in this case, between the instinct of parental love and the custom of infanticide—in individuals, and, in the earlier passage, how we might understand the transition of behavior from being habitual to becoming “a regular custom” and the changing usefulness “to the tribe” of a given custom.