The first beginnings of the pairing family appear on the dividing line between savagery and barbarism; they are generally to be found already at the upper stage of savagery, but occasionally not until the lower stage of barbarism.

• 对偶家庭产生于蒙昧时代和野蛮时代交替的时期，大部分是在蒙昧时代高级阶段，只有个别地方是在野蛮时代低级阶段。