University of São Paulo: Your dog recognizes his emotions and makes decisions based on them, shows a study by USP

Does your dog know what to do when you are angry or happy? In order to understand whether dogs respond differently to positive and negative human expressions, researchers at the Institute of Psychology (IP) at USP and at the University of Lincoln, UK, studied 90 dogs and found that they are not just capable to infer human emotions through facial expressions, but also to relate this information to its possible consequences and make decisions based on a prediction of our behavior.

The article entitled Dogs can infer implicit information from human emotional expressions was published in the scientific journal Animal Cognition and developed by researchers Natalia Albuquerque and Briseida Resende, from the Psychology Institute of USP, and Daniel Mills, Kun Guo and Anna Wilkinson, from the University of Lincoln .


Neutral emotion, joy and anger: Tests have shown that dogs take human facial expressions into account when making decisions. Photo courtesy of the researcher
This ability was once believed to be uniquely human, but scientific evidence built up over the past few decades has shown otherwise. The ability to recognize emotions had already been observed in primates, such as chimpanzees, capable of recognizing emotions among themselves, but only with a 2016 study , also conducted by researcher Natalia et al. This research proved that dogs go further: they recognize human emotions, not just their own species – being the only animals to achieve this feat.

In 2018, another work by the scientist showed that dogs respond to this recognition of emotions from another species. “So, the next step was to find out if they understand that a person’s emotional state changes the way they behave and, therefore, they can adjust to that”, explains Natalia to Jornal da USP .

For the experiment, 90 dogs, two actresses, some objects and a room in the IP Laboratory were needed. The animals were recruited voluntarily, according to some criteria such as being healthy, non-aggressive, used to new places and people and without vision problems – which would make the test difficult.

After getting used to the room, the dogs observed an interaction between two actresses, trained to, at each session, demonstrate neutral, positive (joy) or negative (anger) facial expressions. Dressed in the same way, they silently passed objects to each other and then sat down with a jar of kibble in one hand and a sheet of newspaper in the other.

The collar was loose and so the dog could interact with the actresses, now both with neutral expressions. To get some feed, the dogs had to ask one of the women – and that choice revealed the animals’ ability. Most made the decision to interact with the actress who, at the time of observation, was happy, and avoided contact with the actress who was previously angry. Tests show that dogs take human facial expressions into account when making decisions, as it might be easier to get some treats from someone friendlier.

“The research shows that dogs take into account the expressions of human emotions to make choices. People may perceive the animal as a being that pays attention to what we do and makes decisions based on that. In this way, I think we can develop a healthier and more respectful relationship”, says the co-author of the work, professor Briseida. She emphasizes that it is important not to treat him as a human, but to respect him as a dog.