Physical touch of any kind drives up the brain's oxytocin levels, for both men and women.

WSJ: When He Says, 'More' and She Says 'No'

According to Muslim beliefs, for example, men in a state of pilgrimage should not wear any stitched items or touch alcohol.

CNN: Gearing up for prevention: The Hajj meets H1N1

Men may rely on their partner not just for sex, but for most of their nonsexual touch as well.

WSJ: When He Says, 'More' and She Says 'No'

Over the next few years, the two men grew close, staying in touch as Mr. Longueuil moved to Connecticut in 2004 to work for Empire Capital, a hedge fund where Mr. Freeman helped him land a job, associates say.

WSJ: They Were Best of Friends, Until the Feds Showed Up

But both men had lived for the previous 15 years in the United States, and had seemed out of touch with Peruvian politics.

ECONOMIST: Politics in Peru: Toledo tries again | The