The University of Chicago neuropsych lab tested whether rats would overcome their fears and brave into the center of an arena to free a trapped cage mate. They not only discovered that the rats would consistently open a door to liberate a friend, but the rats would also free the trapped rat when they would be physically prevented from socializing and when they had the choice to free the cage mate or pig out on some delicious chocolate chips. The rats even shared chocolate with their liberated buddies. They did not open the doors on empty or dummy-rat holding containers, proving that the motivator was the opportunity to help out a friend and not just exploration.
Finally, evidence that animals empathize. Don’t just take my word for it. Watch the video here!