Recent research tells us that the sound of our voices betrays clues about our age, whether we’re menstruating (if we’re female), our sexual behavior and our physical strength. All of these factors, evolutionary psychologists say, are indicators of her reproductive potential.
“Are you on your period?” It’s a question most women have been asked at one point or another by their boyfriend or spouse during a disagreement. It turns out that some men actually can tell when it’s a woman’s time of the month—and it’s not because of bratty behavior.
Sex for a female Lake Eyre dragon lizard is sometimes like going to bed with a man and a roaring chainsaw. The male lizard bites her neck before mounting her. If he sinks his teeth in with too much vigor, he can chomp her spinal cord and kill her.
So it's no wonder the lady lizards are choosy about sex.
When it comes to contraception, women have their pick of techniques. In addition to sperm-blocking barriers and foreign objects in the uterus (IUDs), there are about a million ways to pump extra hormones into the bloodstream (pill, patch, ring, shot, or implant).
For men, it's always been pretty much condoms or a vasectomy.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.