WASHINGTON (AP) — New research suggests our capacity to care about others might have very ancient roots.

Scientists are usually reluctant to attribute humanlike feelings to animals, but it’s generally accepted that many animals have moods, including fish.

A study published Thursday shows that fish can detect fear in other fish, and then become afraid too – and that this ability is regulated by oxytocin, the same brain chemical that underlies the capacity for empathy in humans.

This raises the possibility that our ability to care for others was deep-rooted in prehistoric animals, before fish and mammals like us diverged on the tree of life.