ethnicity does -- I'm sure that if one compares a Lapp to a person from say Crete, there will be differences in sleep patterns. I would guess that these sleep patterns continue into second and third generations even if they live in the same area.
it's not "race" as in black v/s white but more to ethnic history.
Also, most "blacks" in this country have some or more "white" blood and vice-versa so that genetic map can go haywire
26 posted on 08/22/2012 12:25:40 AM PDT by Cronos
(**Marriage is about commitment, cohabitation is about convenience.**)