Dumb or smart asses? Donkey's (Equus asinus) cognitive capabilities share the heritability and variation patterns of human's (Homo sapiens) cognitive capabilities

© 2019 Elsevier Inc. Scientific evidence for intelligence in donkeys could expose their historical unmerited cognitive derogatory status. Psychometric testing enables quantifying animal cognitive capabilities and their genetic background. Owing to the impossibility to use the language-dependent scales that are widely used to measure intelligence in humans, we used a nonverbal operant-conditioning problem-solving test to compute a human-analogous IQ, scoring the information of thirteen cognitive processes from 300 genetically tested donkeys. Principal components and Bayesian analyses were used to compute the variation in cognitive capabilities explained by the cognitive processes tested and their genetic parameters, respectively. According to our results, IQ may explain over 62% of the cognitive variance, and 0.06 to 0.38 heritabilities suggest that we could ascribe a significant proportion to interacting genes describing the same patterns previously reported for humans and other animal species. Our results address the existence of a human-analogous heritable component and mechanisms underneath intelligence and cognition in probably one of the most traditionally misunderstood species from a cognitive perspective.