83:5.13
The olden taboos on sex relations with a pregnant or nursing wife tended greatly to foster polygyny. Primitive women aged very early because of frequent childbearing coupled with hard work. (Such overburdened wives only managed to exist by virtue of the fact that they were put in isolation one week out of each month when they were not heavy with child.) Such a wife often grew tired of bearing children and would request her husband to take a second and younger wife, one able to help with both childbearing and the domestic work. The new wives were therefore usually hailed with delight by the older spouses; there existed nothing on the order of sex jealousy.