Ted Audio Collective.

Audio Collective.

You're listening to Ted Talks Daily,

where we bring you new ideas to spark your curiosity every day.

I'm your host, Elise Hugh.

If you have been around both young boys and young girls, you can probably attest to how they play

among themselves very differently. I have all daughters, so when

I'm around their boy classmates who are always chasing and tackling and sometimes playfully

smacking each other, it always feels a little much.

Evolutionary biologist Carol K. Hoven researched why boys more than girls think it's more normal to tackle one another.

And in her talk, she offers a way to explain why the sexes can be so different after the break.

These days we're surrounded by photo editing programs. Have you ever wondered what something or someone actually looks like under all the manipulation?

It's me, Elise, and this October I'm giving a TED Talk in Atlanta about finding true beauty

in a sea of artificial images. I'm so excited to share the stage with all the

amazing speakers of the TED Next conference and I hope you'll come and experience it with me.

Visit go. TED.com slash Ted Next to get your pass today.

And now our Ted Talk of the day.

As I look around the room, I can see, I think it's about half of you have been exposed to high levels of a powerful chemical,

and it is circulating in your blood as we speak.

It's flowing freely through almost all of your cells,

including neurons,

where it affects whether they live or die

...