The Science of Kissing summary

Do you know why we use the letter “x” to represent kissing? There’s a historical reason behind it.

Throughout history, humans have used kissing for many different purposes. In the Middle Ages, it was often used to seal a contract.

In the film Back to the Future, Marty McFly goes back in time and accidentally intercepts the meeting of his parents by making his mother, Lorraine, fall in love with him. When she kisses him, however, it feels wrong to her. “It’s like I’m kissing my brother!” she says.

The scenario is fictional, but the biology behind it is real. Every human and ape has a unique scent because of special glands in our neck, face, armpits and genital area, and when we look for a mate, we seek out one with a smell that’s different from ours. After all, we’re more likely to produce healthy offspring with a person who’s biologically and immunologically different from us.

If you’ve kissed someone, you’ve experienced the same kind of high that people get when taking drugs like cocaine.

Your brain gets a burst of energy and a natural high when you kiss someone. When you kiss, your breath gets deeper and your blood vessels dilate, which makes you flush and sends more oxygen to your brain.

You’ve probably heard of the Kama Sutra, the famous guide to sex, love and marriage rooted in the Hindu tradition. It devotes an entire chapter to the topic of kissing.

Modern science recognizes the importance of kissing just as the Kama Sutra does. After all, it’s part of our evolution: kissing fuels your sex drive and thus makes you more likely to reproduce.

The key message in this book:

Kissing is part of our biology and evolution, which is why it’s so fundamental in both humans and animals. It strengthens our social bonds, makes us healthier and happier, helps us find suitable mates and encourages us to reproduce and further our species. Kissing is a lot more than just a nice feeling!