Primates Fear Snakes Due To Scales, Not Movement: Japan Study

Primates, including humans, instinctively fear snakes due to their scales rather than their slithering movements, according to a study by Nagoya University cognitive science professor Nobuyuki Kawai, as reported by Yosuke Tsuyuke for Mainichi Japan.

The "snake detection theory" suggests that primates evolved advanced vision and larger brains to spot snakes, their primary predators.

The study builds on the "snake detection theory," which suggests that primates evolved advanced vision and larger brains to spot snakes, their primary predators.

Experiments conducted by Kawai revealed that monkeys with no prior exposure to snakes could detect photos of snakes faster than other animals. Human infants also displayed strong brainwave reactions to images of snakes.

To isolate the role of scales, Kawai tested Japanese macaques by showing them digitally altered salamander images featuring snake-like scales.

The results revealed that monkeys could detect salamanders with snake-like scales as quickly as, or faster than, actual snake images.

This sensitivity to scales suggests that the unique texture of snakes is a key trigger for fear responses. The findings were published in the November 10, 2024, edition of Scientific Reports.