It can be costly to engage in that behavior.

We found that women were most attracted to men other than their primary partner when they were in the high fertility phase of the menstrual cycle. That's the day of ovulation and several days beforehand.

Women have a biology that can lead them to stray.

Women can't see a man's genetic make up. So, they come to prefer good genes on the outside.

We try to promote healthy behavior for a lifetime.

Behavior is the mirror in which individuals show their true image.