Ways Orangutans Are Just Like Humans

“Perhaps the most humanlike behavior is the laughing by apes when they are being tickled,” Frans de Waal, a primatologist at Emory University, told LiveScience. “It is low-pitched compared to human laughter, but the facial expression and the waxing and waning of the laughing sounds are eerily human to the point that those of us familiar with these vocalizations cannot stop ourselves from laughing too.”