Is there really love at first sight?

Research suggests that the "love at first sight" phenomenon is almost always "lust at first sight." Relationships based on first impressions almost always end in tatters. The extreme passion one sometimes feels in the beginning of a relationship fades rapidly; it's usually quite weak within 18 months. True psychological and emotional intimacy takes time to develop. Historically, passionate love was seen as a kind of madness, and love and passion weren't considered a legitimate basis for marriage until recent times.

From : http://cms.psychologytoday.com/articles/pto-20030121-000003.html