Do 5-Month-Old Infants Possess an Evolved Detection Mechanism for Snakes, Sharks, and Rodents?

ABSTRACT

The 4 experiments reported here used the preferential looking and habituation paradigms to examine whether 5-month-olds possess a perceptual template for snakes, sharks, and rodents. It was predicted that if infants possess such a template, then they would attend preferentially to schematic images of these nonhuman animal stimuli relative to scrambled versions of the same stimuli. The results revealed that infants looked longer at a schematic snake than at 2 scrambled versions of the image and generalized from real snakes to the schematic image. The experiments also demonstrated that 5-month-olds showed no preferential looking for schematic sharks or schematic rodents relative to scrambled versions of those images. These data add to the growing support for the view that humans, like many nonhuman animals, possess an evolved fear mechanism for detecting threats that were recurrent across evolutionary time.

Notes

¹ Although the number of babies who failed to habituate was relatively high (N = 7) compared with the comparable study in Rakison and Derringer (2008, Experiment 4), their test trial data indicated the same general pattern of looking as that of the infants who habituated in the current study (schematic snake, M = 10.76; partially scrambled snake, M = 14.2; completely scrambled snake, M = 15.4).

Additional information

Funding

This work was supported by the National Institute of Child Health and Human Development [R03HD049511-01].