PERSONALITY: An even-tempered, family-oriented homebody who checks the date book before doing anything.
BIOLOGY: Builders tend to have higher levels of serotonin, a brain chemical known for instilling calm.
IDEAL MATE: A fellow Builder, who appreciates crucial details like alphabetizing the owner's manuals for appliances dating back to 1987.
OUR FAVORITE COUPLE: Paul Newman and Joanne Woodward, whose marriage lasted for 50 years. In Hollywood, no less.
PERSONALITY: A sensation-seeking creative type who would rather let dishes pile up in the sink than miss a chance to go bungee jumping.
BIOLOGY: Explorers have high levels of dopamine, a chemical in the brain associated with feelings of euphoria and optimism. Explorers love sex. Love.
IDEAL MATE: A fellow Explorer. In short, a partner who won't flinch if you ask him to play hooky and go to Bangkok on a whim.
OUR FAVORITE COUPLE: Duh. Brad and Angelina, the jet-setting, tattooed, unwed parents of six.