Women may prefer geeky men as long-term partners, but certainly not when they are "on heat", for that's the time of the month when they go looking for the most ruggedly handsome man they can find in the unconscious belief they will provide their kids with "good genes", reveals a new study.
The study, by a team of biologists led by Randy Thornhill at the University of New Mexico, found that women experience oestrus or "heat" like other mammals, but unlike the latter, human females get extremely choosy about their mate at this time of the month.
Thornhill told an Association for the Study of Animal Behaviour conference in Newcastle that it was wrong to assume that women didn't go on "heat" or "oestrus" - a monthly phase of "extended sexuality".
"Women don't miaow and they don't scratch at the door - but they do have oestrus," The Daily Mail quoted him, as saying.
"Oestrus doesn't indiscriminately increase sexual desire. It functions to get good genes," he added.
Professor Manfred Milinski of the Max Planck Institute for Evolutionary Biology in Germany, said the theory could explain why women are attracted to more macho men when their chances of pregnancy are highest, and to geeky men at other times.
"Thornhill may have performed a service. It needs someone to point out there may be no paradox," he said.
As it turns out, men are unconsciously aware of this phenomena as weedier men turn on the charm on the days their partner is most likely to stray.
"Female affairs can be extremely costly to male partners and men are therefore expected to possess evolved counter-strategies designed to protect them from cuckoldry," say the researchers.