Social Learning in Horses—Fact or Fiction?

Abstract

Prima facie, the acquisition of novel behaviors in animals through observation of conspecifics seems straightforward. There are, however, various mechanisms through which the behavior of animals can be altered from observing others. These mechanisms range from simple hard-wired contagious processes to genuine learning by observation, which differ fundamentally in cognitive complexity. They range from social facilitation and local enhancement to true social learning. The different learning mechanisms are the subject of this review, largely because research on learning by observation can be confounded by difficulties in interpretation owing to the looming possibility of associative learning infecting experimental results. While it is often assumed that horses are capable of acquiring new behavior through intra-species observation, research on social learning in horses includes a variety of studies some of which may overestimate the possession of higher mental abilities. Assuming such abilities in their absence can have welfare implications, e.g., isolating stereotypical horses on the assumption that these behaviors can be learned though observation by neighboring horses. This review summarizes the definitions and criteria for the various types of social transmission and social learning and reviews the current documentation for each type in horses with the aim of clarifying whether horses possess the ability to learn through true social learning. As social ungulates, horses evolved in open landscapes, exposed to predators and grazing most of the day. Being in close proximity to conspecifics may theoretically offer an opportunity to learn socially, however anti-predator vigilance and locating forage may not require the neural complexity of social learning. Given the significant energetic expense of brain tissue, it is likely that social facilitation and local enhancement may have been sufficient in the adaptation of equids to their niche. As a consequence, social learning abilities may be maladaptive in horses. Collectively, the review proposes a novel differentiation between social transmission (social facilitation, local, and stimulus enhancement) and social learning (goal emulation, imitation). Horses are undoubtedly sensitive to intra-species transfer of information but this transfer does not appear to satisfy the criteria for social learning, and thus there is no solid evidence for true social learning in horses.

Horses Failed to Learn from Humans by Observation

“…In the present study, horses failed to learn from observing humans in an instrumental task. This finding corresponds with the recent results from Burla et al [8] and Henriksson et al [9], who also found no effect of human demonstration on horses' success rate in a detour task, and moreover with the majority of the studies on intra-species social learning in horses (for a general review: Rørvang et al [4]). For example, Lindberg et al [19] and Ahrendt et al [20] found no effect of prior demonstration from a conspecific on the number of observer horses accomplishing an instrumental task, nor on their latency to do so.…”

“…Individual learning refers to individual trial-and-error learning [2], whereas social learning has been used in the scientific literature to cover a wide range of learning mechanisms, ranging from simple processes to more cognitively complex processes [3]. As suggested by Rørvang et al [4], we distinguish between social transmission (social facilitation, stimulus enhancement, and local enhancement, i.e., the simpler processes), and actual social learning (goal emulation and imitation). Actual social learning requires higher cognitive abilities to learn about the goal and/or actions of the demonstrator.…”

“…For horses, there are several studies with conflicting results both on intra-and inter-species social learning. Intra-species social learning was discussed in detail in Rørvang et al [4], and the current study will only consider inter-species social learning. In terms of evolution, inter-species social learning is favorable when species live in overlapping niches, where information from one species can have a positive impact on the other [7], and especially so, if this information outweighs the quality of information from the same species.…”

“…In terms of horses, distinguishing between lower cognitive mechanisms (i.e., social transmission of information) and higher cognitive mechanisms (i.e., actual social learning) when horses observe and learn from humans is not only important from a fundamental scientific perspective. Assuming social learning mechanisms in their absence can also have implications for horse training and horse welfare [4]. If a training system assumes that horses are able to learn new behavior from observing a human performing the behavior, and the horse fails to reproduce the behavior, this can lead to frustration or even punishment.…”

Farm Animal Cognition—Linking Behavior, Welfare and Ethics

“…Another crucial part of social cognition involves social facilitation and/or learning [for a distinction see (83), from here on referred to as “social learning”]. These processes can occur through observational conditioning, local/stimulus enhancement, emulation and/or imitation (84).…”