Are men, by nature, not monogamous?

"Men are not by nature monogamous."

This statement, or its equivalent, has appeared in both professional and popular literature over the last decade or so.

Such an idea, as well as a number of related theories, is grounded in the emerging work of a number of disciplines: anthropology, biology, sociology and psychology among them. Studying human behavior in the past and present, focusing simultaneously on individual, group and societal patterns, researchers are attempting to narrow in on just how much of what we do is, in fact, encoded in our genetic inheritance and how much is actually shaped by our environment or by our will.

This is an old argument, but this time around a variety of new analytical tools have enabled scientists to claim with more certainty a biogenetic foundation to a variety of human behaviors - our choice of mates (who, when and how many) among them.

In fact, or so goes the theory, men will be naturally attracted to younger, healthier, more fertile women and will seek to impregnate as many of these women as possible. All in the name of propagating the species, of course.

Now as a marriage therapist I'm just waiting for the first husband to excuse his extra-marital dalliance based on his biology: "I can't help it, its in my genes!"

The reality is, we may have biologically determined tendencies toward aggression or multiple mates or not staying in one place too long or whatever (actually, there is also a school of thought which suggests we are biologically predetermined toward cooperation, community, and monogamy; their ideas just don't make very good headlines).

A biological tendency, however, does not absolve us from bringing into play another determinant of human behavior: reason and will. We can choose to act differently than our biogenetic inheritance dictates and base our decisions on our rational assessment of right and wrong and the consequences of our actions.

Unfortunately, reason and will do not always provide us with either clear direction or sufficient motivation.

Life is both complex and confusing, especially when it comes to relationships between men and women. There does seem to be, however, a fairly substantial body of evidence that suggests that in this day and age, men and women do best in pairs and that monogamy is best suited to keep these pairs functioning.

In other words, men may or may not be by nature monogamous, but marriages better be.

• The Rev. Ken Potts is a pastoral counselor and marriage and family therapist with Samaritan Interfaith Counseling Centers, Naperville and Downers Grove.