As usual Coelho uses subtlety to state his opinion. He starts with Natalie Angier's article in New York Times, dated 25.3.2008. The article is about the research works of psychologists and biologists who looked for monogamous behavior amongst animal species.
Unfortunately, they found that Diplozoon Paradoxum is the only competitor to humans in monogamous behavior. Other than that, most animals tend use multiple partners, and offer what can be termed as costly presents to their lovers.
It is the male animals who are the violent lot almost always, inclined to be jealous. They fight over a female, but that is hardly a secret. In many animals, the pairing is done when the animals are young, and the two grow up together. Despite this, several times the females give birth to young ones who do not have the same DNA.
Scientists also found that prostitution exists amongst animals as well, and faithful companions often receive less in comparison to the lovers.
Based on all these facts, may be humans should take pride in monogamous behavior, as it can become a major difference with animal behavior.