As understood by humans.
From From “Rat and Ant Rescues ‘Don’t Show Empathy’” (Science Daily, August 12, 2012), we learn,
Studies of how rats and ants rescue other members of their species do not prove that animals other than humans have empathy, according to a team led by Oxford University scientists.
‘To prove empathy any experiment must show an individual understands another’s feelings and is driven by the psychological goal of improving another’s wellbeing. Our view is that, so far, there is no proof of this outside of humans.’
The team highlights how interpretations of pro-social behavior vary — rat rescues, for instance, are regarded as being motivated by empathy whilst ant rescues are not — even though the observed behavior (pulling on the legs or tail of the trapped individual, followed by biting at the restraint) are very similar.
In order to prove empathy any experiment would need to show that individuals changed their response if the circumstances changed; for instance moving away from a trapped individual if that reduced the trapped animal’s distress. It would also need to disentangle empathy from acting simply to stop the trapped animal’s stress signals — something that can be psychologically selfish and does not need to involve empathy.
These distinctions are important.
First, human empathy is bound up with reason, not just emotion. Indeed, a widely warned-against fault in helping professionals is this: Becoming so emotionally involved that one becomes a part of the problem, rather than a part of any solution.
So for a state of mind to be counted as empathy in humans, reason is essential. Reason determines, by observation, what demonstrably helps the person or animal that is suffering. The reasonable person does that, not just whatever comes first to mind or relieves one’s own anxiety most quickly. (Those methods may happen to work accidentally – but they don’t tell us much.)
It would be most interesting if rats meet that standard.