Comparing oneself to others is a key process in humans that allows individuals to gauge their performances and abilities and thus develop and calibrate their self-image. Very little is known about its evolutionary foundations. A key feature of social comparison is the sensitivity to other individuals' performance. Recent studies on primates produced equivocal results, leading us to distinguish a 'strong' variant of the social comparison hypothesis formulated for humans from a 'weak' variant

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... d in non-human primates. Here, we focus on animals that are distantly related to primates but renowned for their socio-cognitive skills, birds from the family Corvidae. We were interested in whether crows' task performances were influenced i) by the presence of a conspecific co-actor performing the same discrimination task and ii) by the simulated acoustic cues of a putative co-actor performing better or worse than themselves. Crows reached a learning criterion quicker when tested simultaneously as compared to when tested alone, indicating a facilitating effect of social context. The performance of a putative co-actor influenced their performance: crows were better at discriminating familiar images when their co-actor was better than they were. Standard extremity, i.e., how pronounced the difference was between the performance of the subject and that of the co-actor, and category membership (i.e., affiliation status and sex), of the putative co-actors had no effect on their performance. Our findings are in line with the 'weak' variant of social comparison and indicate that elements of human social comparison can be found outside of primates.