Empathy is the ability to share and understand the emotions of others. It is a construct of multiple components, each of which is associated with its own brain network. There are three ways of looking at empathy.
First there is affective empathy. This is the ability to share the emotions of others. People who score high on affective empathy are those who, for example, show a strong visceral reaction when watching a scary movie.
They feel scared or feel others’ pain strongly within themselves when seeing others scared or in pain.
Cognitive empathy, on the other hand, is the ability to understand the emotions of others. A good example is the psychologist who understands the emotions of the client in a rational way, but does not necessarily share the emotions of the client in a visceral sense.
Finally, there’s emotional regulation. This refers to the ability to regulate one’s emotions. For example, surgeons need to control their emotions when operating on a patient.
Those who show a strong visceral reaction when watching a scary movie score high on effective empathy.
Another way to understand empathy is to distinguish it from other related constructs. For example, empathy involves self-awareness, as well as distinction between the self and the other. In that sense it is different from mimicry, or imitation.
Many animals might show signs of mimicry or emotional contagion to another animal in pain. But without some level of self-awareness, and distinction between the self and the other, it is not empathy in a strict sense. Empathy is also different from sympathy, which involves feeling concern for the suffering of another person and a desire to help.
That said, empathy is not a unique human experience. It has been observed in many non-human primates and even rats.
People often say psychopaths lack empathy but this is not always the case. In fact, psychopathy is enabled by good cognitive empathic abilities - you need to understand what your victim is feeling when you are torturing them. What psychopaths typically lack is sympathy. They know the other person is suffering but they just don’t care.
Research has also shown those with psychopathic traits are often very good at regulating their emotions.