I'm still awaiting my copy of Reviving Ophelia (ordered it through my book
club), but was amazed at the suggestion that extra light, as from
electricity, could lead to earlier menstrual periods.  If this were the
case, then you would find earlier age at menarche in the tropics, with a
clinal distribution of increasingly later age at menarche as you go north or
south, up to the Arctic, where they have 6 months of darkness every year.
This is not what one finds.  Quite the contrary -- people in the tropics
tend to have later ages at menarche than people in temperate climates (don't
have the data on Inuit handy), due to poorer diets.

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Katherine A. Dettwyler                                email: [log in to unmask]
Anthropology Department                               phone: (409) 845-5256
Texas A&M University                                    fax: (409) 845-4070
College Station, TX  77843-4352