Misusing biology to oppose same-sex marriage

If Maggie Gallagher is going to use biology to defend her opinion on same-sex marriage, as she did in a Nov. 1 Times Op-Ed article, it would be better if she knew a little something about biology. Her argument shows a common and disturbing ignorance about the actual biological roots of human behaviors as well as a remarkable ignorance about the biology of other species.

Gallagher writes: “When a baby is born, a mother is bound to be close by. But if we want fathers to be there for children, and the mothers of their children, biology alone will not take us very far.” This statement is completely wrong. In fact, fathers stay close to their children’s mothers because of -- not in spite of -- biology. Until very recently in human history, it was extremely difficult for a single person to successfully raise a human infant. Men who abandoned their mates found that their progeny were more likely to die and their genes didn’t survive to the next generation. Those men who stayed around to help rear the young were more likely to see their offspring survive to adulthood and pass on their genes, including the genes for sticking around to help care for the kids. Biology has created human males who tend to help care for their own offspring.

Biology has also created human males and females who tend to not actually be completely monogamous. Why stick with just one partner if you can spread your genes a little farther? In fact, the difficulty of raising infants can predict the likelihood that a male of any species will stay with and support the female while the couple’s offspring are growing. The only truly monogamous animals are those for whom it is impossible to raise their young single-handedly (for example, the albatross) and those in which the father takes complete control of rearing the offspring (sea horses come to mind). In all other cases, including with humans, fathers stay close and help rear offspring only as much as is necessary.

Other species have developed different strategies for dealing with the problems of rearing their young. Chimpanzees and lions live in larger family communities of several adult males, many adult females and their offspring. For these animals, females mate with all males in the group to ensure that all the males will protect their offspring. Male lions and chimps have a habit of killing other males’ offspring. When a male thinks the young might be his, he is unlikely to kill them.

In many species, the need to gain others’ help in protecting the young has been solved by females congregating in large numbers. In many species of birds, for example, females gather at a “lekking” site, where males perform and preen to impress the ladies. The most “attractive” male mates with the most females but offers no hand in rearing the young. The females usually nest or give birth close together, their sheer numbers offering protection against predation. Even the hungriest fox can’t eat all the babies if they are born all at once, and this increases the chance that the offspring will grow to adulthood.

Marriage is valuable to human society, providing a framework in which children are reared, as Gallagher correctly states. But that framework does not have to be made of one male paired with one female. There is no biological reason that two women or two men cannot adequately form a union that protects and nurtures children. Animals do it all the time. Among lions, the males have virtually no role in caring for the young. The females work together to protect and nurture their cubs. Female elephants tolerate males only long enough to get pregnant. Elephant calves are raised by their mothers, aunts and grandmothers -- and never by a father.

Gallagher may be correct that children “need a mother and a father, long for a mother and a father, deserve a mother and a father.” But research has shown that what children need more is to be raised by people who love them and each other. The children of parents who hate each other surely long for and deserve parents who love each other. Children of impoverished parents surely long for and deserve parents who don’t have to worry about how to pay for clothes, food and medical care. Children who have lost a parent surely long to have that parent back. Life doesn’t give everyone what they long for and deserve, yet we survive and thrive in spite of this. And yes, children of loving gay couples are just as likely to thrive as those of straight couples, just as animals raised exclusively by adults of one sex are able to survive and thrive.

If you oppose gay marriage on moral grounds, so be it; your morals are your own. But don’t try to get biology to back up your argument. Biology is far more open-minded than we ever give it credit for.

Katherine Gould is the author or “A Tiger in the Bedroom: Lessons From Mother Nature’s Sex Shop.”