A new theory from researchers at the School of Biological Sciences at Queen’s University Belfast suggests animals experience emotions much like humans - exhibiting positive moods when they “win” and negative moods when they encounter a “loss”.
Their findings have been published in Proceedings B, the Royal Society's flagship biological research journal.
Animal contests are interactions between organisms when both are trying to use the same resource related to growth, reproduction, or survivability.
Competition stems from the fact that resources are limited. There are simply not enough of some resources for all individuals to have equal access and supply.
Until now, researchers have focused on how animals assess the resource’s value and their opponent’s fighting ability.
However, the new paper argues that these assessments also contribute to animals’ "emotional" state – and these emotions drive animal behaviour.
Using animal contests as a case-study, the researchers suggest just as depressed or anxious humans are more pessimistic about the future, animals that lose fights will be in a more negative state, more pessimistic about whether they can win, and so are less willing to engage in future fights.
Andrew Crump, a postdoctoral researcher from the School of Biological Sciences at Queen’s and lead author of the paper, said: “Human emotion influences unrelated cognition and behaviour. For example, people rate their overall life satisfaction higher on sunny days than rainy days. We have found that animals’ emotions also influence unrelated cognition and behaviour.
"For example, animals that won a contest experienced a more positive mood and expected fewer predators in their environment.
"Similarly, animals that lost a contest experienced negative emotions and took part in less future contests. These carryover effects may lead to maladaptive behaviour.
“Stimuli or events that elicit emotional responses might influence virtually any decision - potentially with life-or-death consequences. For example, are rustling leaves a predator or the wind? Anxious animals will probably interpret the rustling as a predator and run away."
Opportunities for animal welfare
Dr. Gareth Arnott, senior lecturer from the School of Biological Sciences and principal investigator on the paper, added: “Animal behaviour researchers typically do not currently consider animal emotions in their work.
"However, the results of this study show that this may need to be considered as the role of animals’ emotion is crucial in relation to understanding their subsequent behaviour.
Understanding these emotions also has practical benefits for the future of animal welfare. Good welfare requires animals to have few negative emotions and lots of opportunities for positive experiences.
"Understanding animal emotions and why they evolved will, therefore, help us to measure and improve animals' emotional states and welfare.”
The research team involved researchers from Liverpool John Moores University, University of Alabama, Scotland’s Rural College, and the University of Bristol and was funded by Northern Ireland's Department for the Economy.