Ravens, like humans, have bad moods they share with others: Study

Ravens are not only intelligent with tool creation and use and solving problems, but they have a social intelligence as well, say researchers.  And it turns out when they have bad moods about something their pessimism spreads to fellow ravens.

In the study when ravens saw fellow birds’ responses to a disliked food, but not the food itself, their interest in their own food options waned.  The researchers say the results suggests that the birds pick up on and even share negative emotions. <Or maybe, like humans, they just get irritated when someone tries to serve them crappy food and they want to warn others about it.>

Backstory: Social behavior of ravens

Previous scientific studies suggest ravens have a capacity for empathy, such as by appearing to console a distressed comrade. This latest study examined whether their reactions to averse events would be expressed and shared with fellow ravens.  In other words, scientists wanted to examine whether ravens shared their emotions–a necessary element for empathy (to be able to feel for others, an animal needs to be able to feel like others).

Study methods overview:

The current study is the first to use the cognitive bias test to examine emotions and social behavior in ravens.

To tune into the moods of ravens, the researchers set up experiments to watch whether the birds reacted positively or negatively to a neutral stimulus.

Eight ravens, tested in pairs, were first given a choice between a box containing a cheese treat and an empty box. Once the birds learned the location of each option, they were given a third box in a new spot that hadn’t been used in the training. Whether a bird acted as if the box was a trick or a treat indicated a cognitive bias, interpreted as pessimism or optimism.

Next, one bird in a pair was offered both unappealing raw carrots and tastier dried dog food before one was taken away. Birds left with the treat moved their heads and bodies as they studied it, while those getting the carrots appeared crankier, spending less time attending to the offering and sometimes kicking or scratching elsewhere. The other bird in the pair watched these reactions from a separate compartment, without being able to see the researcher or which food the bird received.

Both birds then performed the cognitive bias test again. This time, observer birds that had seen their partner appearing perky showed on average the same level of interest in their own ambiguous box as they had previously. But those that had seen their partner reacting negatively typically took more than twice as long to approach the ambiguous box. This dip in the observer birds’ interest was somehow influenced by seeing their partner’s apparent disappointment, the researchers say.

Each bird was tested four times, half of the time with the undesired food and the other half with the treat.


Study results

While the negative responses seemed contagious, the positive responses did not.



Journal reference:  Adriaense, J.E., et al. (2019). Negative emotional contagion and cognitive bias in common ravens, Proceedings of the National Academy of Sciences, the United States of America, https://doi.org/10.1073/pnas.1817066116.

abstract/overview of study