Love Machine Author Nicholas Boothman doesn't believe in wasting time. The former fashion photographer -- who devoted two books to his 90-second (!) formula for making friends and getting on with colleagues -- now has put a stopwatch to the arguably more ambitious project of attracting a life partner. For that you'll need a little longer, he says in his new book, "How to Make Someone Love You Forever in 90 Minutes or Less" (Workman Publishing, $16.95). In a time-pressed world, who can argue against improved efficiency? But forever's an awfully long time. . . .

Know Thyself Love happens fast, holds Boothman, when there is a pairing of matched opposites. He bases the assertion, he says, on interviews with more than 2,000 people. "This is not a scientific tome," said Boothman. "I didn't do experiments."

To speed the vetting process, he divides the world into four personality types -- the analyst (a detail-oriented perfectionist and logician), the controller (strong-willed, action-oriented and sometimes argumentative), the supporter (a good listener who hides emotions) and the promoter (often disorganized but persuasive and entertaining) -- and advises steering clear of your type when seeking a partner.

Whoa, Baby Not so fast, says Arthur Aron, a psychology professor at the State University of New York's Stony Brook University. In a series of lab studies, Aron isolated some factors that account for mutual attraction. Knowing that the other person likes you is key, he says; whether Cutie has a dissimilar personality is not. And a relationship's durability can be dramatically affected by external stress factors -- such as the death of a child or financial hardship, Aron says. "Your initial relationship to the person has little bearing to what happens over time."

-- Rita Zeidner