During the past few years we've learned amazing facts about the astonishing cognitive, emotional, and moral lives of other animals. Now, we've recently learned that chimpanzees know what's on other chimpanzee's minds, or not (see also). There's also a wonderful video at this same website.
Researchers from the University of St. Andrews in Scotland, the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the Budongo Conservation Field Station in Uganda investigated how 33 wild chimpanzees reacted to model vipers placed on the paths on which they traveled in the forest. They discovered that "The apes were more likely to make warning calls when they spotted a venomous snake if others in their troop had not seen the danger ... As chimps in the know arrived at the scene, they passed the warning on to others who lagged behind but were still within earshot."
Catherine Crockford, one of the researchers, summarized the significance of this research as follows: "... the findings suggest humans are not alone in knowing the minds of others, an ability that may have been pivotal in the evolution of language as it allowed humans to share information and boost collective knowledge. ... More of the essential ingredients needed to kickstart complex communication are evident in chimpanzees than we thought."
These data are especially important because researchers disagree about whether other animals have what's called a theory of mind (see also), that they know what's on the mind of other animals. While it's been difficult to confirm in laboratory studies using in many cases highly unnatural and contrived experiments, many field workers have claimed there's no way high degrees of sociality could have evolved without this cognitive capacity. So, these recent data are especially important because the experiments were conducted in the field with behaviorally and ecologically relevant stimuli.
Stay tuned because the more we look for sophisticated cognitive capacities among nonhumans, the more we learn about their presence, not only in mammals but also in birds, fish, and other animals.