Helen Fisher, Ph.D., a biological anthropologist and senior research fellow at The Kinsey Institute at Indiana University, had been meeting up with a man in New York every couple of months for about a year. They went on dates to the opera and out to eat at restaurants, but they typically ended their evenings with nothing more than a hug goodbye. One night over drinks at dinner, she suggested they secretly write down what they would like if they won a game of pool against the other.
Shortly after a victorious...