Dovetailing into this perspective is Lancy’s “pick-when-ripe” versus “pick-when-green” outlook. In pick-when-ripe cultures, children aren’t recognized until they’ve mastered smaller-scale versions of adult actions and education—after which they are “picked” and considered individuals. In “pick-when-green” cultures (neontocracies like the United States), personhood is recognized immediately, then carefully cultivated.

Among early hunter-gatherer societies, the birth rate was kept low by extending lactation—though other factors, like poor nutrition and infanticide, also played a part. Simply put, the groups couldn’t risk overburdening the food resources of its ranks, and children couldn’t cover their sustentation through gathering. As historian Peter N. Stearns puts it in Growing Up: The History of Childhood in a Global Context, children, “…were economic liabilities in the first human economy.”

Conversely, children were an integral part of the agricultural economy, which emerged next. Their function among the family unit grew—by about age five, they could perform menial tasks around the house, then advance to working in the fields by their teens. Expectedly, the birth rate rose, though prolonged lactation and a strict attention to reproduction were emphasized—too many children would strain resources. Here also, an additional function of the child emerged: a late-in-life birth was generally planned so parents would have someone to look after them in their old age. In these patriarchal societies, adulthood meant being able to marry and support a family. This is also where class differences had a marked effect—the rich could support more children than the poor. Status was solidified by plentiful progeny, appointments, and alliances—and men were the architects, so a male heir was essential. Female infanticide or abandonment was practiced with regularity among the Greeks and Romans, and in China.