Humans, animals like same mating calls, backing `Darwin's hunch'

Charles Darwin had a hunch that birds had “nearly the same taste for the beautiful” as humans. New research points towards humans and other animals indeed sharing aesthetic preferences.

In an experiment, people choosing a favourite from two mating calls of an animal species tended to match the preferences of the species itself.

In other words, when a female frog prefers a certain croak from her suitor, humans may agree that it sounds better.

“This result seems wild and it is,” says Dr Sam Mehr, of the University of Auckland and Yale University, the senior author of the new study. “The big-picture implication is of some universals across species in the appreciation of sound.”

The lead researcher, Dr Logan James, of McGill University in Canada, the University of Texas and the Smithsonian Tropical Research Institute, says one explanation may be that humans share many aspects of perception with other animals.

“The results are very exciting,” says James. “Across nature, the smells of flowers, the colours of butterflies, and the songs of birds didn’t evolve for humans, yet we find them beautiful. And it seems there are shared preferences we are only just learning about.”
 

More than 4,000 people listened to pairs of mating calls from 16 species in a gamified experiment through online citizen science platform The Music Lab, which is run by the University of Auckland and Yale University.

They chose their favourites from each pair, listening to frogs, birds, insects, mice and monkeys. All up, there were 110 pairs of sounds.

Previous research had established which calls females found more attractive. For example, female túngara frogs in Panama prefer a complex call over a simple call most of the time. Humans had the same preference.

On average, human listeners preferred the same calls that animals did within their own species. There was variability across individuals and across species, but overall, human preferences correlated with animal preferences.

Humans matched for example the preferences of the Pacific field cricket, the song sparrow, and the hourglass treefrog, and disagreed with the Gelada monkey and the Zebra finch.

The stronger an animal species’ preference, the more likely humans would agree – and the faster the choice. Agreement between animals and humans was strongest when the calls involved lower pitched sounds or acoustic adornments, such as trills, clicks and chucks.

Go to this link to make your own choices and see how the data for the study were collected.

“From an aesthetics perspective, you wouldn’t really expect similarities here,” says Mehr. “So, it's quite surprising that there are some cross-cutting, universal principles of what sounds nice across species, even if those principles are a bit hard to nail down quite yet.”