For every word written in scientific journals about the evolution of astonishing language ability, at least a hundred words have been written in women’s magazines about men’s apparent inability to articulate even the simplest thought or feeling. Women commonly complain that their sexual partners do not talk enough to them. If language evolved through sexual selection, and if sexual selection operates more powerfully on males than on females, you may legitimately wonder why your boyfriend or husband cannot share his feelings with you. Is it possible that, his early courtship efforts having brought success, he no longer feels driven to be as verbally energetic, interesting, and self-disclosing as he was before? The man who used to talk like Cyrano now talks like a cave-man. Once he was a poet, now he is prosaic. His verbal courtship effort has decreased.
I have already argued that effective verbal courtship is a reliable fitness indicator precisely because it is costly and difficult. Animals evolve to allocate their energies efficiently. If it took a million words to establish a sexual relationship with you, your boyfriend was apparently willing to absorb those costs, just as his male ancestors were. But if it takes only twenty words a day to maintain exclusive sexual access to you, why should he bother uttering more? His motivational system has evolved to deploy his courtship effort where it makes a difference to his reproductive success- mainly by focusing it where it improves his rate of sexual intercourse. Men apparently did not evolve from male ancestors who squandered high levels of verbal courtship effort on already established relationships. Of course, if an established partner suspends sexual relations, or threatens to have an affair, evolution would favor motivations that produce a temporary resurgence of verbal courtship until the danger has passed. Frustratingly, a woman may find that the greater the sexual commitment she displays the less her man speaks.
This analysis may sound heartlessly unromantic, but evolution is heartlessly unromantic. It is stingy with courtship effort, stacking it heavily where it does the most good, and sprinkling it very lightly elsewhere. Human courtship, like courtship in other animals, has a typical time-course. Courtship effort is low when first assessing a sexual prospect, increases rapidly if the prospect reciprocates one’s interest, peaks when the prospect is deciding whether to copulate, and declines once a long-term relationship is established. We all enjoy a desired partner besieging us with ardent, witty, energetic courtship. That enjoyment is the subjective manifestation of the mate preferences that shaped human language in the first place. As with any evolved preference, we may desire more than we can realistically get. Evolution’s job is to motivate us, not to satisfy us.
So, when women universally complain about their slothfully mute boyfriends, we learn two things. First, women have a universal desire to enjoy receiving high levels of verbal courtship effort. Second, high levels of verbal courtship effort are so costly that men have evolved to produce them only when they are necessary for initiating or reviving sexual relationships. Far from undermining the courtship hypothesis for language evolution, this phenomenon provides two key pieces of evidence that support it.
– The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature (pg. 382) by Geoffrey F. Miller