One of the many wonderful things pointed out in the book Sex at Dawn is how the conservatives in America fell in love with the March of the Penguins. They instantly found a human connection with penguin monogamy and devotion to child rearing.
"March of the Penguins," the conservative film critic and radio host Michael Medved said in an interview, is "the motion picture this summer that most passionately affirms traditional norms like monogamy, sacrifice and child rearing."The authors of Sex at Dawn , Christopher Ryan and Cacilda Jethá, challenge this reading of penguin probity with other facts about the bird that were left out of the epic documentary (to learn more about this, read the book). But there is something else about penguin (or any another form of) monogamy (Sex at Dawn discusses it in relation to the only monogamous ape, the gibbon) that's not stressed enough in public discourses. That something is the role of monomorphism in monogamy.
With humans and other mammals, there is a clear morphological difference between males and females. This difference biases females for child rearing, particularly in the early stages of development. In away, one can understand this bias as a possible source of polygamy. The male body is not shaped for child rearing or long commitments; it is designed for the widest distribution possible of genetic information. (This is by no means the whole picture, of course; with human males, for example, wide distribution in specific contexts has positive, prosocial consequences—again, read the book.) But if we look at penguins, what do we see? The females cannot easily be distinguished from the males. This characteristic, monomorphism, is common with monogamous birds—it's hard to tell them apart. And the consequence of this lack of morphological bias is shared child rearing.
Why point this out? If male penguins are practically no different than female ones, then their relationship (or form of love) is actually much closer to homosexual relationships in the human domain. This is certainly one way of looking at things. In a sense, what the conservatives were celebrating was the kind of sameness we find in gay lust, love, and commitments. It is this sameness that makes monogamy common (and even necessary) feature of the bird kingdom.
A truly heterosexual animal is the gorilla. The difference between males and females is considerable. That difference is the result not of monogamy (which leads to sameness) but maintaining/defending/sustaining a harem (which leads to difference, greater dimorphism).
