If you're trying to consciously assess the future of a relationship, Dr. Berman says there's one surefire way—a kiss. "You really learn a lot from a kiss," she says. "You're seeing if you like the way he smells. All your senses are engaged, and you get a sense of his sensuality, his connection, whether he's a take-charge kind of guy or more of a stepping back kind."
In fact, Dr. Berman says 66 percent of women say they would dump a guy after a bad first kiss.
When it comes to relationships, Dr. Berman says kissing frequency is a direct indicator of happiness. "It turns out that couples who kiss and cuddle regularly are eight times less likely to be stressed and depressed than couples who don't get that," she says. "You have to have a minimum of a 10-second kiss every day."