Editorial Development: Bonnie Brook Communications

59
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WEEK 9
DAY 1
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Laughter
In June 2009, researchers in England released the results of experiments in which they had recorded 
the sounds made by young gorillas, orangutans, chimpanzees, bonobos, and human babies as they were 
being tickled on the feet and palms. Scientists have traditionally been unwilling to identify the noises apes 
make as laughter, but research now suggests that they have been wrong. It turns out that apes do, in fact, 
laugh. 
The analysis of the sounds from the laughter experiments showed that the ape noises were related to 
human laughter in the same way that ape genes are similar to human genes. In other words, ape laughter 
and human laughter developed in the same way many millions of years ago.
Although ape laughter and human laughter sound quite different, there are multiple similarities. The 
laughter of gorillas, chimpanzees, and bonobos sounds like fast panting, grunting, or simply noisy 
breathing. Orangutan laughter is a series of quick snorts. Human laughter often sounds more melodic than 
ape laughter because of the vibrations of human vocal cords, but humans have also been known to have 
laughter that sounds like panting, snorting, or other sounds that match the noises apes make.
The laughter of chimpanzees stood apart during the experiments because they laugh on both the 
inhale and the exhale of breath. Humans, gorillas, and bonobos, on the other hand, laugh only on the 
exhale. It takes longer than usual to exhale while laughing. Such laughter shows a type of breath control 
necessary for speech. Scientists used to believe that such breath control was unique to humans. These 
findings do not suggest that apes are capable of speech, but they do support the idea that humans have 
more in common with apes than previously thought.