Evidence of heterospecific referential communication from domestic horses (Equus caballus) to humans.

This research investigates whether domestic horses can use referential communication, signaling their wants through gestures, to interact with humans, specifically regarding the location of out-of-reach food. Evidence showed that horses do utilize gestures to draw human attention to a desired object.

Concept of Referential Communication

• Referential communication refers to the process by which the sender of a message uses specific gestures to direct the recipient’s attention towards achieving a certain goal. This could involve pointing or showing an object to the recipient to inform them about what the sender wants.
• If this form of communication is successful, the sender and the recipient’s attention are simultaneously focused on a third entity, the target.

Research Aim and Methodology

• The goal of this study was to examine if domestic horses have the capability to use referential communication with a human observer, specifically focusing on the location of out-of-reach food.
• To test six operational criteria for referential communication, the researchers manipulated the recipient’s (experimenter’s) attentional state under four different conditions: frontally oriented, backward oriented, walking away from the arena and frontally oriented with other helpers present in the arena.

Findings and Conclusions

• Results showed that the rate of gaze alternation was higher when the recipient was frontally oriented compared to the other conditions. This suggests that the horses were capable of manipulating human attention depending on their orientation.
• The research also revealed that horses use both indicative (like pointing) and non-indicative gestures (such as nods and shakes) in suitable test conditions.
• Furthermore, horses were found to switch from visual to tactile signals in their communication and exhibited perseverance in their attempt to communicate.
• The study concluded that horses indeed utilize referential gestures to manipulate human attention to obtain an unreachable resource. This is the first evidence of such capabilities in an ungulate species (hoofed mammals).