Let me out! Proximate factors in helping behavior in pigs

Prosocial behaviours, defined as actions that benefit other individuals, are widespread in humans but also observed in non-human animal species. However, little is known about their underlying mechanisms and to which extent animals and humans may share some of the same emotional or cognitive adaptations promoting prosociality. Helping behaviours, when an individual assists another to reach an otherwise unachievable goal, are especially interesting because they are sometimes linked to empathy in humans. However, evidence for empathy remains disputed in animals in scientific fields. We developed a helping paradigm in which pigs can spontaneously learn to open a door in a helping context, in which they release a partner trapped for a short time in a compartment, or in a non- helping context, in which they open a door to an identical, empty compartment. The paradigm does not require training or food rewards, as pigs proved able to learn how to open the door on their own. Furthermore, we test pigs in social groups in their home environment, which gives animals the choice about whether, when and whom to help. In the first part of this project, we will use this testing approach to evaluate the role of individual personality and experience, behaviour and possible solicitation by the trapped pig, and social relationships in influencing helping behavior. In the second part of the project, we will use non- invasive methods to measure physiological changes in the helper and the trapped pigs, depending on whether the pigs decided to help or not. This project should allow to determine to what extent helpers show sensitivity to the emotional states of other animals in need, and are able to regulate their own emotional response in order to help. Our project also has animal welfare implications by clarifying how emotional contagion and emotional regulation may influence prosocial behavior and the spread of positive or negative emotional states in groups of animals.