The ethnographic evidence suggests that human nature is adapted to an ancestral mating system that was predominately polygynous (one husband, multiple wives). Most ancestral men aspired to polygyny (even though most weren’t impressive enough to attract more than one wife), and some ancestral women preferred to be the co-wife of a really impressive man than the sole wife of a second-rate one.
Men typically lie upwards and women typically lie downwards. Men pretend that they make more money than they actually do, they pretend that they are taller than they actually are, and they pretend that they have had more sexual partners than they actually have. In contrast, women pretend that they are younger than they actually are, they pretend that they are lighter than they actually are, and they pretend that they have had fewer sexual partners than they actually have.
