As social animals, we need to exchange juicy tales about someone - to connect with one another. For millions of years our forebears must have sat around the campfire, whispering about everyone they knew.

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.

Once you fall for someone, their smell can be a powerful thing. Women will wear their boyfriends' T-shirts, and throughout tales in history men have held on to their lover's handkerchief.

Mothers really were not built to raise babies not only by themselves, but with only a partner. For millions of years, a woman had much more than just her husband to help rear her young... This whole idea of 'it takes a village to raise a child' is exactly how we're supposed to live.

When you massage someone, the levels of oxytocin go up in the brain, and oxytocin is one of the chemicals that drives attachment.

You can really get poked in the back and not feel it very much, but just a feather around your lips and you really do feel it.