Recent research has shown that apes (and other higher mammals) may be closer to humans in terms of the ability to think rationally, self recognize, and empathize to the point that there is a growing reluctance to use them in scientific research.
It’s hard to deny that some animals are attentive to mood and can express affection in a way that a fish cannot. Not that it makes much difference to me personally although I do eat fish but abjure tabby cat. I can feel better that apes are less used in medical research but it’s more difficult to find the line between some species.
I’m of an age where absolutes are relics of an earlier time and having been to war, understand that in life compromises are often necessary. But it makes me feel better to look into the eyes of a bonobo and know that others of his kind are not sacrificed unnecessarily. This is the difference between us. I know I will die where he might only have a sense of death. – Carlos
Great Apes Make Sophisticated Decisions
Chimpanzees, orangutans, gorillas and bonobos make more sophisticated decisions than was previously thought. Great apes weigh their chances of success, based on what they know and the likelihood to succeed when guessing, according to a study of MPI researcher Daniel Haun, published on December 21 in the online journal PLoS ONE. The findings may provide insight into human decision-making as well.
The authors of the study, led by Daniel Haun of the Max Planck Institutes for Psycholinguistics (Nijmegen) and Evolutionary Anthropology (Leipzig), investigated the behaviour of all four non-human great ape species. The apes were presented with two banana pieces: a smaller one, which was always reliably in the same place, and a larger one, which was hidden under one of multiple cups, and therefore the riskier choice.
The researchers found that the apes’ choices were regulated by their uncertainty and the probability of success for the risky choice, suggesting sophisticated decision-making. Apes chose the small piece more often when they where uncertain where the large piece was hidden. The lower their chances to guess correctly, the more often they chose the small piece.
The researchers also found that the apes went for the larger piece — and risked getting nothing at all — no less than 50% of the time. This risky decision-making increased to nearly 100% when the size difference between the two banana pieces was largest. While all four species demonstrated sophisticated decision making strategies, chimpanzees and orangutans were overall more likely to make risky choices relative to gorillas and bonobos. The precise reason for this discrepancy remains unknown.
Haun concludes: “Our study adds to the growing evidence that the mental life of the other great apes is much more sophisticated than is often assumed.”