Many years ago when I was still an undergraduate, I took a general psychology course as one of those annoying Liberal Arts electives that nerds—even at technical schools—are forced to endure. It turned out that I enjoyed it but now remember only one thing from it: the takete-maluma effect. The idea is that you are shown two shapes, one jagged and one rounded, and asked which is takete and which is maluma. It turned out that virtually all human beings, regardless of background and spoken language, chose takete for the jagged shape and maluma for the round one. You can see the shapes at the link above. It’s amazing how this stuck with me all those years. I misremembered maluma as being spelled “malumba” but otherwise recalled everything exactly.
The thing that’s striking about the effect is how universal it is. The only exceptions are people with certain physical defects and some people on the autism spectrum. Everyone else agrees: takete is jagged, maluma is rounded. Now it turns out that even dogs agree. Some researchers from the University of Parma in Italy reproduced the experiment for dogs. You can read the details at the link. The the words are different—bouba and kiki—but the results are amazingly consistent with but not as perfect as those for humans. What is it about these sounds that suggest a shape even to animals?