The rat freed one of its own and shared its food. Why?

New research by scientists at Ruhr University Bochum offers a more precise answer: yes, rats do possess a form of empathy, but it is not as complex as that of humans. This is not ‘sympathy’ in the everyday sense, but a simpler behavioural pattern: the animal recognises another’s emotion and situation, acts flexibly and helps not only for direct gain.

The study has been published in Biological Reviews.

Its main contribution lies not in a new experiment with rats, but in a model that allows us to compare empathy across different animals without resorting to extremes: neither ‘just like humans’ nor ‘merely instinct’.

Details

The story began with a well-known 2011 study published in *Science*. At that time, researchers from the University of Chicago demonstrated that laboratory rats repeatedly freed familiar conspecifics from a restraint device, even when there was an opportunity to obtain chocolate nearby. In the university’s press release, this was described as one of the first pieces of evidence of empathy-driven helping behaviour in rodents.

An important detail: the rats were not simply pushing the door by chance. In the experiments, they gradually learnt to open the enclosure and did so more quickly. When chocolate was added to the task, the animals still freed their trapped fellow rat and were then able to share the treat.

To some scientists, this appeared to be a strong argument in favour of empathy in rats. For others, it seemed like an overly bold interpretation: perhaps the animal was simply reacting to stress, noise, habit or social excitement, rather than ‘feeling sympathy’ in the human sense.

A team led by philosopher Albert Newen proposed a way out of this impasse. Instead of asking ‘do rats have empathy or not?’, the researchers view empathy as a set of several abilities. This approach allows us not simply to say ‘yes’ or ‘no’, but to determine exactly what type of empathy is possible in different species.

How scientists propose to measure empathy

In the new model, empathy is described across five dimensions. An animal must, to at least some extent, recognise another’s emotion, understand its situation, take its mental state into account, act flexibly, and direct its behaviour towards the other rather than solely for its own benefit.

According to this model, rats do not possess all these components. They are likely to have a moderate ability to read another animal’s emotions and situation. Their behaviour can be flexible: they do not simply react automatically, but learn to help in specific situations. However, they show almost no signs of a complex understanding of another’s mental state — that which, in humans, is linked to an awareness of others’ thoughts, intentions and experiences.

To put it simply: a rat may react to the state of a familiar conspecific and help it, but this does not mean that it ‘thinks about its feelings’ in the same way that a human does.

Why it is not simply instinct

The key argument in favour of empathetic behaviour is selectivity. If it were merely a rigid, innate reflex, rats would help everyone in the same way. However, researchers note that rats are more willing to help familiar animals with whom they have social ties than strangers.

This makes the behaviour more akin to social assistance than to a mechanical reaction. The animal does not simply ‘open the door’, but reacts to the situation of another member of its group.

But caution is needed here. Scientists are not saying that rats are kind, noble or capable of moral choice. Such words are too human. It is more accurate to say that rats exhibit behaviour which meets certain criteria for empathy, but this is a simpler and more limited form.

Why this is important

Rats often evoke disgust or fear in people: they are associated with rubbish, disease and pests. That is why we readily recognise emotions in dogs or cats, but are far less prepared to recognise complex behaviour in rats.

The new model helps to remove personal likes or dislikes from our assessment. The question is not whether we like an animal. The question is what abilities it demonstrates in controlled observations.

This is also important for the science of the evolution of social behaviour. If elements of empathy are present not only in humans and great apes, but also in rodents, then basic forms of helping others may have arisen in social animals much more widely than is commonly thought.

Background

In their new study, the authors compare different groups of animals: great apes, rats and mice, dogs and wolves, as well as corvids. The aim is not to rank ‘who is kinder’, but to describe different profiles of empathy.

In humans, empathy involves complex components: we can imagine another’s point of view, understand their intentions, assess the situation, recall past experiences and consciously decide to help. In animals, some of these components may be more pronounced, whilst others may be weaker or almost absent.

Therefore, the statement ‘rats are capable of empathy’ is only true with a qualification: we are not talking about human compassion, but about a simpler form of social response and assistance.

Source

Study: Albert Newen et al., “Animal empathy reconsidered: a multidimensional profile account”, Biological Reviews, 2026.