Apparently letting someone sample the milk before buying the cow isn't such a bad idea.

A team of psychologists from the Interdisciplinary Center Herzliya and the University of Rochester conducted four interrelated studies and found that sexual desire can trigger behaviors that can promote emotional bonding.

Study co-author Harry Reise says, "Although sexual urges and emotional attachments are distinct feelings, evolutionary and social processes likely have rendered humans particularly prone to becoming romantically attached to partners to whom they are sexually attracted."

The other study co-author, Gurit Birnhaum adds, "Sex may set the stage for deepening the emotional connection between strangers.Having sex on a first date has long been frowned on by people assuming it'll put the other person off wanting to pursue a relationship."

Scientists have found that actually the reverse may be true.

Birnhaum continues, "fundamentally, sex is about procreation and we've been designed to work together to protect our young - so perhaps it's an evolutionary thing."

Click here for much more on how the interrelated studies were conducted and how some of the scientists' conclusions were determined.