Those who live in cold regions attain puberty at a much later age as compared with those living in hot regions where both male and female attain it at a quite early age. "The average temperature of the country or province,’ says the well-known authors of the book Woman, "is considered the chief factor here, not only with regard to menstruation but as regards the whole of sexual development at puberty. … Similarly, the author of Kinsey Report states: ‘The incidence of pre-adolescent sex play at particular ages (active incidence) seems to have been highest in the younger age groups.
Watu wanaoishi kwenye maeneo yenye baridi hubarehe wakiwa na miaka mingi zaidi kuliko wale wanaoishi kwenye maeneo yenye joto ambako wavulana na wasichana hubarehe/huvunja ungo wakiwa na umri mdogo. "Joto la wastani la nchi au jimbo,’ wanasema watunzi wa kitabu kinachofahamika sana Woman, "linachukuliwa kuwa kigezo kikubwa zaidi hapa, si tu kuhusiana na kupata siku za mwezi bali pia kuhusu suala zima la maendeleo ya kijinsia wakati wa kuvunja ungo. … Kwa namna hiyo hiyo, mtunzi wa Kinsey Report anaeleza: ‘Kutokea kwa vitendo vya ngono vya katika miaka maalum kabla ya kubarehe (kuanza kivitendo) kunaonekana kuwa kwingi zaidi kwa makundi ya umri mdogo.