Horses cross-modally recognize women and men.

Several studies have shown that horses have the ability to cross-modally recognize humans by associating their voice with their physical appearance. However, it remains unclear whether horses are able to differentiate humans according to different criteria, such as the fact that they are women or men. Horses might recognize some human characteristics, such as sex, and use these characteristics to classify them into different categories.

Horses form cross-modal representations of adults and children.

Recently, research on domestic mammals' sociocognitive skills toward humans has been prolific, allowing us to better understand the human-animal relationship. For example, horses have been shown to distinguish human beings on the basis of photographs and voices and to have cross-modal mental representations of individual humans and human emotions. This leads to questions such as the extent to which horses can differentiate human attributes such as age.

Pet-directed speech improves horses' attention toward humans.

In a recent experiment, we showed that horses are sensitive to pet-directed speech (PDS), a kind of speech used to talk to companion animals that is characterized by high pitch and wide pitch variations. When talked to in PDS rather than adult-directed speech (ADS), horses reacted more favorably during grooming and in a pointing task. However, the mechanism behind their response remains unclear: does PDS draw horses' attention and arouse them, or does it make their emotional state more positive? In this study, we used an innovative paradigm in which female horses watched videos of humans speaking in PDS or ADS to better understand this phenomenon.