France, May 24 -- "Zamba draws nothing but dots. Loi sketches curves and triangles. Misaki fills the page with large fan-shaped patterns. These aren't children in an art class. They are chimpanzees, and they each have their own style," writes ethologist Cedric Sueur on Instagram, sharing images of each chimp's distinctive art.

Sueur is one of four primatologists, three from France and one from Japan, who collaborated on a study published this month in the scientific journal Primates.

The colleagues analysed nearly 500 drawings produced by six chimpanzees at the Great Ape Research Institute, a sanctuary in southern Japan that takes in chimpanzees and bonobos that were once used as laboratory test subjects.

The team provided the animals ...