I recently stumbled on this item in Science News - Chimp friendships are based on trust.
It almost goes without saying that trust is a defining element of genuine human friendship. Now, a report in the Cell Press journal Current Biology on January 14 suggests that the same holds true among chimpanzee pals. The findings suggest that friendship based on trust goes way, way back, the researchers say. "Humans largely trust only their friends with crucial resources or important secrets," says Jan Engelmann of the Max Planck Institute for Evolutionary Anthropology in Germany. "In our study, we investigated whether chimpanzees show a comparable pattern and extend trust selectively toward those individuals they are closely bonded with. Our findings suggest that they do indeed, and thus that current characteristics of human friendships have a long evolutionary history and extend to primate social bonds."
Not a particularly surprising outcome, but what exactly has been discovered here? Have we uncovered the fact that chimps trust their friends to a greater extent than other chimps?
Or have we reminded ourselves that "friendship" and "trust" are words with linked meanings? As the piece says - trust is a defining element of genuine human friendship. Trust could also be seen as a defining element of the word "friend" - a job for dictionaries rather than science.
Someone we don't trust is not classed as a friend and someone we class as a friend is usually trusted more than a non-friend because in part that's what we mean by friendship. It's how we use the words. In which case the division made by this piece of work becomes somewhat artificial.