It's a primal impulse to worry about an infant's growth.

But inhibitions fail, and the primal impulse asserts itself when it comes to tape recording.

It was the primal impulse of fight or flight, and she was being compelled to fly from something.

But among male writers the claim is that the primal impulse behind humor is largely self-protective - learned in school by little boys trying to get by.

Wrestling exhibitions are a safe refuge, a place for men feeling emasculated to play out the primal impulse to smack each other in the head.

This sense of being at war with an intractable, adversarial world has always been a primal impulse in slapstick.

They are a window into his purest creative method, which sprang from impulses far more primal than any desire to browbeat.

And so the primal human impulse to explore goes on.

The study, which appears in the current issue of the journal Human Nature, shows how new technology subserves primal impulses - specifically, the impulse to strut.