Horse sense: social status of horses (Equus caballus) affects their likelihood of copying other horses’ behavior

Abstract

Animals that live in stable social groups
need to gather information on their own relative position
in the group’s social hierarchy, by either directly
threatening or by challenging others, or indirectly and
in a less perilous manner, by observing interactions
among others. Indirect inference of dominance relationships
has previously been reported from primates,
rats, birds, and fish. Here, we show that domestic
horses, Equus caballus, are similarly capable of
social cognition. Taking advantage of a specific ‘‘following
behavior’’ that horses show towards humans
in a riding arena, we investigated whether bystander
horses adjust their response to an experimenter according
to the observed interaction and their own dominance
relationship with the horse whose reaction
to the experimenter they had observed before. Horses
copied the ‘‘following behavior’’
towards an experimenter after watching a dominant
horse following but did not follow after observing
a subordinate horse or a horse from another social
group doing so. The ‘‘following behavior,’’ which
horses show towards an experimenter, therefore appears
to be affected by the demonstrator’s behavior
and social status relative to the observer.