Glancing through my notebook on the last day of the meeting, I was embarrassed to see page after page with flowers and odd geometric shapes sketched in the margins. But doodlers need not feel ashamed, says Mimi Lam of University of British Columbia in Vancouver. “Everybody does these things absent mindedly to think,” she says. Right – that’s why I did it. To think.

Lam has been looking at the quixotic carvings on ancient hominid artifacts like the parallel scratchmarks on a 1.4 million year old bone fragment found in the Kozarnika Cave. Are they art? Symbolism? No, says Lam. They’re meaningless doodles, perhaps comparable to a bear leaving his mark on a tree by scratching its trunk. At best, she said, the marks could be a sign of ancient hominids honing their hand-eye coordination.

Well, if those are doodles, I have to hand it to the doodlers. It’s one thing to doodle with pen and paper. It’s entirely something else to go to the trouble of chiseling your doodles in stone.