A park warden was watching a herd of elephants walk by when he noticed something. One of the adult females was very gently carrying a baby elephant who had clearly been dead for several days. When the herd stopped to eat or drink, the female placed the body on the ground next to her while she dined. After finishing her meal, she would pick up the calf and proceed to carry it to the herd's next destination. As one would imagine, the female's pace was slowed by the extra weight of the calf. Did the herd ever leave her behind? No. Instead, they walked slower, to accommodate the pace she was capable of maintaining. (When Elephants Weep, Masson and McCarthy, 1995).
Was the elephants' behavior in this situation a product of genetic survival, of some instinctive social urge? Or did the female adult feel sorrow and love for the deceased calf, causing her attachment to it? And did the rest of the herd respond with compassion by slowing their pace to accommodate the grieving female?
I'm not an evolutionary psychologist. I don't propose to be able to analyze and determine the survival value of the herd's behavior in terms of gene- or species-centered evolution. What I do know is that the behavior seen in the elephants is the same as we might see from a grieving human parent and her support network. Do we ever assume that the human parent acting in such a manner actually does NOT feel sorrow, but rather is just responding in an instinctual mode of survival?
The real question is, how much evidence do we need to accumulate to determine if a non-human animal experiences emotion vs. instinct? And, just as importantly, can we ever structure an experiment such that the results are definitive? And how do we know that, if non-humans feel emotions, that they are exact duplicates of our emotions—maybe they feel love, but it's different than our love. How can we even know that the romantic love I feel for my significant other is the same as the romantic love you feel for your significant other? If we can't really define the emotions we, as a species feel, how can we define the emotions potentially felt by different species?