Lifetime pair bonding is rare among mammals—only 3 percent of mammals stay faithful to each other. While the human species may rank higher in habits of fidelity, humans too are becoming less faithful. Today, fully half of all marriages fail and it’s estimated that nearly one-fourth of husbands engage in an adulterous relationship (and one-fifth of wives do too). Scientists believe that men and women generally approach sex differently. Males will often crave sex more frequently than women do.

Please watch the following video clip and answer the corresponding follow-up questions.

Dance of Life

1			What is the most likely scientific explanation for varying sexual appetites between men and women?
2			Explain why the proverbial “itch” when husbands and wives begin to get restless with each other has changed on average from seven to four years.