Colin Barras in New Scientist:
Some of our actions have near-instant consequences. Even young children learn for themselves that drinking water is a great way to quench your thirst. But sex doesn’t immediately lead to babies. It generally takes weeks to even register a pregnancy. Months pass before the act of childbirth.
In all of the world’s human societies, there is a strong understanding that sex makes babies. But it presumably required careful observation, deep thinking and an ability to reliably and accurately track the passage of time for ancient people to make the link between the two. It may also have required language so that individuals could discuss and refine their ideas.
And this brings us to non-human animals. Given that no other animal species has our capacity for language and abstract reasoning, do any of the rest of them understand where babies come from?
More here.