Pigs, like humans, are also more optimistic or pessimistic depending on their mood

Technically speaking, we, humans, are not that much different from animals. A new research from the University of Lincoln and Newcastle University revealed that mood and personality affect the decisions of pigs. In other words, outlook of the animal changes depending on how it feels that day. Similar phenomenon has been long noticed in humans.

Outlook of a pig depends on its personality type and mood. Image credit: Petr Kratochvil via Wikimedia, Public Domain

Outlook of a pig depends on its personality type and mood. Image credit: Petr Kratochvil via Wikimedia, Public Domain

Different researches have showed how our mood and personality affect our ‘cognitive biases’. However, it was considered to be somewhat of a unique feature of humans. Now scientists wanted to see if a similar mechanism can be observed in pigs, how mood and personality affect how optimistic or pessimistic pigs are. It turns out, when pigs are in a bad mood they too have a more pessimistic outlook on life. By this pigs were divided into two groups: ‘proactive’ or ‘reactive’. Proactive ones are more active and consistent in their behaviour, while reactive are more passive and changeable in their responses.

It is also very interesting how scientists measure mood of the pig. They placed animals into two different scenarios that are known to affect mood of the pigs. Pigs were presented with a choice of two bowls of food, one containing sugar-coated sweets and another full of coffee beans that pigs do not like. Then scientists put a third bowl and pigs did not know what it contained. Proactive pigs were quick to rush to the new bowl, expecting it to have some more sweets (they were optimistic), while reactive ones expected some more bitter beans.

However, mood is also a very important variable. Reactive pigs, living in a richer environment, encouraging a good mood, were much more likely to be optimistic. This is very interesting, because in humans such bias has been extensively researched, but no one tried finding the same phenomenon in animals. Project leader Dr Lucy Asher, lead author of the study, said: “Our results suggest that judgement in pigs, and potentially in other animals, is similar to humans – incorporating aspects of stable personality traits and more transient mood states. The study provides a fascinating insight into the minds of these intelligent animals and paves the way for even more in-depth studies in the future”.

Humans are just another species of animals on the planet Earth. As unique as we are, many traits are shared throughout the animal kingdom. Researches like this help understanding which aspects of our minds are found in animals as well and when in the course of evolution we obtained them.