Empathy is unusual in the animal kingdom. So empathy must have had some major survival benefits for it to have evolved. What might those benefits have been?
Empathy seems to have evolved in three major steps.
First, among vertebrates, birds and mammals developed ways of rearing their young, plus forms of pair bonding – sometimes for life. This is very different from the pattern among fish and reptile species, most of which make their way in life alone. Pair bonding and rearing of young organisms increased their survival and was consequently selected for, driving the development of new mental capacities.
As neuroscientists put it, the “computational requirements” of tuning into the signals of newborn little creatures, and of operating as a couple – a sparrow couple, a mountain lion couple, that is – helped drive the enlargement of the brain over millions of years. As we all know, when you are in a relationship with someone – and especially if you are raising a family together – there’s a lot you have to take into account, negotiate, arrange, anticipate, etc. No wonder brains got bigger.
It may be a source of satisfaction to some that monogamous species typically have the largest brains in proportion to bodyweight!