Sex By Numbers: On the Brain

A weekly look at sex and culture, by the numbers.

The human brain—comprising 3% of our body weight yet using 20% of our energy—is our body’s most complex organ. When it comes to the brain and sex though, things are pretty straightforward: we want it. This week’s Sex By Numbers takes a look at just how badly.

2 weeks: Amount of time it took the rats in a Princeton University study to exhibit reduced anxiety levels and increased brain activity after daily exposure to sex.

45: Percentage of respondents to a survey who said they mentally plan and schedule an appointment to have sex with their partners.

200: Number of male students asked to rate female’s attractiveness based on video clips of silhouetted dancers. The men’s brains responded to the female’s fertility cycles, assigning higher ratings to women who were ovulating than to those that weren’t.

15: Amount of times per day the average American male thinks about sex; meanwhile, females think about the deed 4 times per day.

5 per 100,000: Rate of incidence per year of sexual amnesia, or the temporary evaporation of all memory after sex. The cause is unknown.

2: Number of areas in the brain—known as the insula cortex and the striatum—that are said to be activated by feelings of both love and sex. Using this new finding, a study in the Journal of Sexual Medicine explores the “addictive properties of love.”

5: The number of IQ points by which females trailed men when women began taking the tests in 1905. Today, that gap has not only been closed, but new research suggests that women now actually lead men in IQ levels.

30: Apparently, palaeontologists just can’t stop thinking about how a 30 ton lizard like a T. Rex managed to reproduce back in the day. Theories and research are plentiful, some of which we’d rather forget.


Rosie Spinks

Rosie Spinks is a freelance journalist from California with a degree in Environmental Studies. Her work has been published in publications including Sierra magazine, GOOD magazine, the Ecologist, and the Guardian Environment Network. A passion for travel, running barefoot outdoors, and reconnecting people to what is good dominates most of her thoughts. You can follow her writing on Twitter and Tumblr.