Young Babies Found to Laugh Similar to Chimps

The way young babies laugh is similar to chimps and this changes as the baby develops to resemble adult human laughter, finds study

Highlights:

Young babies laugh during both inhalation and exhalation, similar to chimps but this changes as the baby develops to resemble adult human laughter which occurs mainly during exhalation
Analyzing the laughter pattern and other non-verbal forms of showing emotion may help identify babies at risk of developmental disorders

Young babies at two to three months of age laugh in a manner identical to non-human primates such as chimps. However, this alters as the baby develops to resemble adult human laughter, reveals a recent study. The findings of the study may have application in determining babies at risk of developmental disorders.

Disa Sauter, a psychologist and associate professor at the University of Amsterdam in the Netherlands, during a discussion at the Acoustical Society of America's 176th Meeting, organized in conjunction with the Canadian Acoustical Association's 2018 Acoustics Week in Canada presented the findings of the study.

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‘Young babies laugh during both inhalation and exhalation, which is remarkably identical to how non-human primates such as chimps laugh.’
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How do Babies Laugh?

Sauter and her colleagues studied laughter clips of 44 infants and children between 3 and 18 months of age. The recordings were obtained from online videos captured while the babies were interacting playfully
The recordings were analyzed by 102 listeners, drawn from across psychology students, who determined the degree to which the laughter in each clip was produced during inhalation versus exhalation
The study found that the youngest babies at around three months of age laughed during both inhalation and exhalation, similar to non-human primates such as chimps. However, older babies laughed predominantly during exhalation similar to older children and adults

It is unclear why only humans among primates laugh during exhalation but it may be due to the voice control they develop with speech. The shift in pattern of laughter is gradual and not associated with any specific developmental milestones. Also the current laughter pattern analysis was performed by non–expert listeners

Sauter said, "Adult humans sometimes laugh on the inhale but the proportion is markedly different from that of infants' and chimps' laughs. We are currently checking these results against judgments by phoneticians, who are making detailed annotations of the laughter."

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Further Research

The team is also examining if there is a link between the proportion of laughter produced during inhalation and exhalation and the reasons why people laugh, which also change with age.

Typically, infants and younger babies laugh as the result of physical interaction like tickling. However, in older individuals, laughter occurs both due to physical play and social interactions

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Summary

Dr.Sauter in conclusion said, “I'd be interested in seeing whether our findings apply to other vocalizations than laughter. Ultimately, the research could offer insight into vocal production of children with developmental disorders.”

If it is known how normally developing babies sound like, it would be interesting to study infants at risk of development disorders to find out if there are any early signs of atypical development in their nonverbal vocalizations of emotion.

References:

Acoustical Society of America - (https://acousticalsociety.org/)
Human babies laugh like chimpanzees - (https://tech2.org/human-babies-laugh-like-chimpanzees/)
Early child development – Disabilities and developmental disorders - (http://www.who.int/topics/early-child-development/disability-developmental-delay/en/)

Source-Medindia