Study shows that apes are more optimistic after hearing laughter
Indiana University: While laughter is often considered uniquely human, tied to language and sense of humor, all great apes produce remarkably similar vocalizations during play that share evolutionary origins with human laughter. In a new study, an international team led by two Indiana University researchers has discovered that bonobos, our closest living relatives along with chimpanzees, tend to be more optimistic after hearing the laughter of their fellow apes—and these findings have implications for understanding the evolution of positive emotions…