Wilks M, Caviola L, Kahane G, Bloom P.
Psychological Science. 2021;32(1):27-38.
doi:10.1177/0956797620960398
Abstract
Is the tendency to morally prioritize humans over animals weaker in children than adults? In two preregistered studies (total N = 622), 5- to 9-year-old children and adults were presented with moral dilemmas pitting varying numbers of humans against varying numbers of either dogs or pigs and were asked who should be saved. In both studies, children had a weaker tendency than adults to prioritize humans over animals. They often chose to save multiple dogs over one human, and many valued the life of a dog as much as the life of a human. Although they valued pigs less, the majority still prioritized 10 pigs over one human. By contrast, almost all adults chose to save one human over even 100 dogs or pigs. Our findings suggest that the common view that humans are far more morally important than animals appears late in development and is likely socially acquired.
From the Discussion section
What are the origins of this tendency? One possibility is that it is an unlearned preference. For much of human history, animals played a central role in human life—whether as a threat or as a resource. It therefore seems possible that humans would develop distinctive psychological mechanisms for thinking about animals. Even if there are no specific cognitive adaptations for thinking about animals, it is hardly surprising that humans prefer humans over animals—similar to their preference for tribe members over strangers. Similarly, given that in-group favoritism in human groups (e.g., racism, sexism, minimal groups) tends to emerge as early as preschool years (Buttelmann & Böhm, 2014), one would expect that a basic tendency to prioritize humans over animals also emerges early.
But we would suggest that the much stronger tendency to prioritize humans over animals in adults has a different source that, given the lack of correlation between age and speciesism in children, emerges late in development. Adolescents may learn and internalize the socially held speciesist notion—or ideology—that humans are morally special and deserve full moral status, whereas animals do not.
