Data for research article: Horses form lasting impressions of people based on facial expressions of emotion during a single encounter.

<div><b>Data for paper appearing in Current Biology March 2018</b></div><div><br></div><div>Data files relating to the two phases of our experiment. <br></div><div><br></div><i><br></i><b>Abstract from article</b><br>For humans, facial expressions are important social<br>signals, and how we perceive specific individuals<br>may be influenced by subtle emotional cues that<br>they have given us in past encounters. A wide range<br>of animal species are also capable of discriminating<br>the emotions of others through facial expressions<br>[1–5], and it is clear that remembering emotional experiences with specific individuals could have clear<br>benefits for social bonding and aggression avoidance<br>when these individuals are encountered again.<br>Although there is evidence that non-human animals<br>are capable of remembering the identity of individuals<br>who have directly harmed them [6, 7], it is not<br>known whether animals can form lasting memories<br>of specific individuals simply by observing subtle<br>emotional expressions that they exhibit on their<br>faces. Here we conducted controlled experiments<br>in which domestic horses were presented with a<br>photograph of an angry or happy human face and<br>several hours later saw the person who had given<br>the expression in a neutral state. Short-term exposure<br>to the facial expression was enough to generate<br>clear differences in subsequent responses to that<br>individual (but not to a different mismatched person),<br>consistent with the past angry expression having<br>been perceived negatively and the happy expression<br>positively. Both humans were blind to the photograph<br>that the horses had seen. Our results provide<br>clear evidence that some non-human animals can<br>effectively eavesdrop on the emotional state cues<br>that humans reveal on a moment-to-moment basis,<br>using their memory of these to guide future interactions<br>with particular individuals.<i><br><br><br></i>