Part of the struggle in getting people on board with the idea that some animals deserve to be recognized as persons is convincing them that the emotional responses, inner psychological life and social bonds of these animals are similar to our own. Because we lack the neuroscience to prove definitively that nonhuman persons have the cognitive toolkit required for these responses, we're stuck with empiricism: if it looks like a duck and quacks likes a duck, we have to conclude that it's a duck. Behaviorism is currently our best tool for assessing the psychological sophistication of animals—and to a certain degree our own. It's worth noting that we cannot prove humans have these capacities either. We just take it for granted that others feel the way we do.

Some behavioral studies are more powerful than others. The video below is a good example—even if it is difficult to watch. It shows a chimpanzee mother dealing with and apparently mourning the death of her 16-month-old child. This haunting footage challenges those who might question the extent to which animals experience the loss of a life:

This footage was captured by researchers from the Max Planck Institute for Psycholinguistics. A team led by Dr. Katherine Cronin sought to study the reaction of non-human primates encountering the realities of mortality.

"The videos are extremely valuable because they force one to stop and think about what might be happening in the minds of other primates," Dr. Cronin told CORDIS News. "Whether a viewer ultimately decides that the chimpanzee is mourning, or simply curious about the corpse, is not nearly as important as people taking a moment to consider the possibilities."

Their report describes what researchers observed:

Dr. Cronin and doctoral student Edwin Van Leeuwen monitored the behaviour of a female chimpanzee that had recently lost her 16-month-old infant. The mother carried the infant's dead body for more than 24 hours, and then laid it on the ground in a glade. She approached the body many times, and held her fingers against the infant's face and neck for several seconds. The mother then stayed close to the body for almost an hour, later carrying it over to a group of chimpanzees that began to examine the body. The mother no longer carried the body of the infant the next day.

When watching the video I was particularly struck with the mother's tenderness and the way she stroked the infant's face. Looking at her reactions, she appeared distraught, frustrated, and forlorn. She seemed quite upset over the idea of having to abandon the body, returning to it periodically in the hopes that the infant would show some signs of life.

A human mom in the same situation would likely act and respond in a similar way. It's worth noting that, like chimpanzees, humans are also members of the great ape family.

Via TreeHugger.