The Great Depression of the 1930s saw more American unmarried women working from nine to five, mostly in repetitive, boring, subordinate, dead-end jobs. But the number of working women doubled between 1870 and 1940. During World War II it doubled once again.

In general, men are wired to notice obvious signs that convey interest in mating - a warm smile, for example - and ignore other subtleties, like if your lipstick is faded.

Natural beauty really entices men. They will tell you this time and time again, and studies consistently prove it.

If we remained perpetually infatuated, we couldn't eat, sleep or work.

Experiences shape the brain, but the brain shapes the way we view experiences, too.

There's magic to love... Millions of years ago we evolved three basic drives: the sex love, romantic love, and attachment to a long-term partner. These circuits are deeply embedded in the human brian. They're going to survive as long as our species survive on what Shakespeare called, this "mortal coil."

Women are very attracted to a low voice because it's linked to testosterone, which for millions of years was a sign that men had very good spacial skills and would have been very good at hunting and finding their way back home.