Humans see further by standing on the shoulders of giants. We build upon the cultures, skills, technologies and knowledge of past generations, in a way that other animals do not.

Many scientists have suggested that this cumulative culture depends on the size of our groups. The more of us there are, the faster our culture ratchets upwards in complexity. If our populations shrink, we lose skills and tech. We see this in theoretical models. We see it in past civilisations—Tasmania being the classic example.

And now, we can see it in two experiments. Working independently, two groups of scientists have shown that larger, more sociable groups are indeed better at maintaining complex cultural traditions, and even improving on them.

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