This is a very informative article from La Leche League.
http://www.lalecheleague.org/ba/Feb93.html
The paragraph that stood out for me was this:
http://www.lalecheleague.org/ba/Feb93.html
The paragraph that stood out for me was this:
Infants sleeping for long periods in social isolation from parents constitutes an extremely recent cultural experiment, the biological and psychological consequences of which have never been evaluated. Most Americans assume that solitary sleep is "normal," the healthiest and safest form of infant sleep. Psychologists as well as parents assume that this practice promotes infantile physiological and social autonomy. Recent studies challenge the validity of these assumptions and provide many reasons for postulating potential benefits to infants sleeping in close proximity to their parents - benefits which would not seem likely with solitary sleeping. Current clinical models of the development of "normal" infant sleep are based exclusively on studies of solitary sleeping infants. Since infant-parent co-sleeping represents a species-wide pattern, and is practiced by the vast majority of contemporary peoples, the accepted clinical model of the "ontogeny" of infant sleep is probably not accurate, but rather reflects only how infants sleep under solitary conditions. I wonder whether our cultural preferences as to how we want infants to sleep push some infants beyond their adaptive limits