Affective empathy is different from cognitive empathy. The former allows us to feel what others are feeling while the later allows us to understand what they're feeling.

In that sens, affective empathy doesn't necessarily lead to constructive behaviors (e.g., crying because we feel our friend's sadness may not make them feel better.)

Cognitive empathy, on the other hand, may lead to a more rational understanding that can then lead to more useful and compassionate behaviors.

According to Paul Bloom affective empathy can be subject to biases. For instance, we have a harder time relating to the experience of people we perceive as different from us. We may feel more empathy for one person close to us than for a hundreds strangers. Affective empathy can also be weaponized against us (for instance by demagogs trying to divide for political gain.)