Briffault’s law maintains that “the female, not the male, determines all the conditions of the animal family. Where the female can derive no benefit from association with the male, no such association takes place.” Today we would say “relationship” rather than “association.”

For this bit of we have Robert Briffault (1876-1948), an English surgeon, anthropologist, and author, to thank. I do not present Briffault’s law as fact, nor do I dismiss it as fiction. It is something to think about – and Briffault gives us even more to ponder.

We already know, of course, that women wield the ultimate veto power in the game. It is women who give thumbs-up or thumbs-down to any advances or proposals from men. Briffault embellishes this truism by asserting that intimate relationships between men and women result from a calculated cost/benefit analysis by women. Will she or won’t she acquire a net gain from any relationship with the man? This does not necessarily mean monetary gain, although it might. Other types of gain might be social status, sexual compatibility, anticipated future , emotional security, and the male’s capacity for fatherhood. Men, put that in your pipe and smoke it.

Briffault continues with these three corollaries to his law:

Even though a woman has accrued past benefits from her relationship with a man, this is no guarantee of her continuing the relationship with him. (Translation: What have you done for me lately?)

If a woman promises a man to continue her relationship with him in the future in exchange for a benefit received from him today, her promise becomes null and void as soon as the benefit is rendered. (“I will gladly pay you Tuesday for a hamburger today.“)

A man’s promise of a future benefit has limited ability to secure a continuing relationship with a woman, and his promise carries weight with her only to the extent that the woman’s wait for the benefit is short and to the extent that she trusts him to keep his promise.

In economics there exists the concept of diminishing marginal utility: The benefit derived from a product lessens with each successive unit consumed. Consider an all-you-can-eat buffet. If you arrive hungry, the first plate from the buffet provides 100% utility in satisfying your hunger. The second plate provides less utility, although you still may be a bit hungry when you begin filling the second plate. But by the time you’re eaten the second plate, you are no longer hungry. If you return to the buffet for a third plate, you will probably feel overstuffed after eating it. In terms of utility you are now in negative territory.

If we accept Briffault’s law at face value, women derive diminishing marginal utility from their relationships with men after acquiring the desired benefits. That Briffault – what a romantic!