When Did Our Early Ancestors Figure Out Sex Makes Babies?


The most popular question of 2012 on Slate’s “The Explainer” was “Why do rich ladies sunbathe topless?” After that important exercise in investigative journalism was completed, Slate doubled back to answer another high-ranked question that’s a modicum more interesting, although the interested parties could probably just have watched Blue Lagoon for a fun cinematic answer with way more celebrity nudity.

When and how did humankind figure out that sex is what causes babies? It’s not exactly the most obvious correlation: Sex doesn’t always lead to babies, and there’s a long lead time between the act and the consequences-weeks before there are even symptoms, usually. So roughly where do we think we were as a species when it clicked?

Considering there are still plenty of scarily uninformed kids across America who still think tongue-kissing makes a baby, it’s not a bad question. As early as the Neolithic era, there seems to have been some awareness that fornication was The Babymaker, as indicated by cave drawings of a man and woman embracing and alongside it, a mother, father and child. The anthropologist in the article refers to this inherent natural awareness as humans’ “reproductive consciousness,” citing the observation of animal reproduction as one possible model that our earliest incarnations took note of.

Research becomes divisive at the turn of the 20th century, when anthropologists studying the natives of New Guinea and Australia note that they make no connection between sex and reproduction—and yet, others found that the natives did believe that semen was responsible for “coagulating” the menstrual blood into what would form the fetus. The Trobriand Islanders believed that this was only one of the ingredients necessary to make a baby, alongside the spirit of the child being dropped through the top of the woman’s head. (Which, the piece points out, really isn’t all that different from the Roman Catholic belief that a soul enters the egg immediately after fertilization.)

What I’m trying to say is, one foolproof contraceptive method is to cover your head at all times. Thank you, Slate!

How Did Humans Figure Out That Sex Makes Babies? [Slate]

Image via trekandshoot/Shutterstock

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