Book excerpt: For anyone who has worried that being beguiled by puppy love might lead only to a short-lived dalliance, Stanley Coren provides the ultimate matchmaking service. Combining his expertise in human psychology and animal behaviour with the research of other animal experts, Coren classifies dogs according to such personality traits as friendliness, protectiveness, and steadiness. To discover which dogs will suit them best, readers take simple personality tests that reveal what they are looking for in a relationship. Extroverted men, for example, may be surprised to find that poodles make the ideal companions; shy women are likely to prefer the company of a bulldog; and men lacking trust might consider an independent Shar-Pei. Stories about people and their four-legged best friends - and a gallery of photographs - capture the special dynamics between couples ranging from Freud and his Chow-Chow to Picasso and his Afghan hound.