Hearing a helpless infant cry is painful (unless you’re just plain heartless), but for mothers, animal or human, responding to infant distress calls runs even deeper; it’s a primal instinct. This instinct is so powerful that it goes well beyond the species barrier. A mother deer, for example, will rush to the aid of other infant mammals if they hear them in distress.

All pet owners at one time or another suspect that pets can sense when humans are down and that they try to comfort them. Many think that such animal compassion is a result of domestication, and others might picture pets with human-like emotional depth (think The Lion King); but the new understanding that mammals respond to cross-species distress shows that it could actually be intrinsic.

Susan Lingle is a biologist at the University of Winnipeg, Canada and she noticed similarities in the distress calls of various infant mammals, so she put it to the test. In a study with her colleague Tobias Riede, the two recorded and played cries of infants from several mammal species for a wild mule deer; the mother deer responded to cries of infant fur seals, dogs, cats, and humans in addition to the deer’s but wouldn’t move towards a birdsong, a coyote’s bark, or other non-infant calls.

Lingle expressed that many mammal cries are similar and are generally made in the face of potentially life threatening situations, so the mother’s quick response is crucial to survival. Lingle muses that the benefits of protecting their offspring must overpower the risk of erring.

Riede and Lingle’s work shows that deer can perceive the emotions behind sounds and that animals may in fact have similar emotional experiences as one another. So maybe “The Lion King theory” isn’t that far off after all. Know more.