WOMEN only stay with men for security, and men only stay with women for sex.
It’s a cynical view of human relationships, but researchers now say it is the
driving force behind the evolution of monogamy—and women started it. By
offering sex all the time, females in monogamous species disguise whether they
are fertile and trick males into sticking around.
In most species, females only have sex when they are fertile. This is because
sex takes energy, and carries the risk of disease. But it also means males can
easily tell which females are fertile, so they don’t waste…
