Why is it so hard to get effective birth control in the US? | Mark Edwards

When does vision loss become blindness? This week we're revisiting a talk by writer, audio producer and editor Andrew Leland as he explains how his gradual loss of vision revealed a paradoxical truth about blindness — and shows why it might have implications for how all of us see the world.

What makes for a meaningful life? Social psychologist Brian S. Lowery explores three ideas tied to the experience of meaning and shows why simply pursuing personal achievements isn't the best way to find it.

In athletics, in business, in life, everyone sets goals. But that's not the way to excel, according to former NFL player Emmanuel Acho, now an author and TV sports analyst. Here's what he says to do instead.

To protect against a possible resurgence of smallpox, the US government is funding research to improve treatments and vaccines. And since it's unethical to expose people to a highly lethal virus, labs are using monkeys as research subjects. But is it right to harm these animals to protect humanity from a potential threat? Rebecca L. Walker takes a look at this classic ethical dilemma. This TED-Ed lesson was directed by Sharon Colman, narrated by Alexandra Panzer and the music is by Miguel d'Oliveira.

Drawing on her research into the science of play, evolutionary biologist Carole K. Hooven delves into how testosterone impacts the body and brain, interacting with culture to create differences in human behavior — starting with why boys tend to prefer rougher play than girls.