New evidence shows that facial expressions begin in utero. Laughing and smiling begin in the womb as early as 24 weeks and are very prevalent by 32.
Worldcrunch has reported that a British research team, from the University of Durham, confirms that babies develop the muscle mechanisms to smile before they are born. This would mean that smiling and perhaps laughter as they claim are innate human responses and not learned behaviors.
The research published in PloS ONE journal affirms that several facial movements beginning in the second trimester enable the formation of all the elements of laughter around the 30th week of pregnancy.
This strongly suggests that the smile observed by researchers is not a reflexive response mimicking a human but rather of an independent action. This is further supported by certain forms of brain damage where a smile can occur without reason demonstrating that it is more of a reflex than a social signal of emotion.
Dr. Matsumoto also comments on the ability of blind athletes to demonstrate facial expressions of emotion such as joy (smiling) and sadness, which is a strong indicator that these are inherent human reactions.
Researcher Nadja Reissland stated, “The movements of the face were spontaneous and could not have been triggered by the ultrasound because the babies were probably not even aware of it. In order to exclude any possibility of external influence we decided to take this approach rather then studying pre-term babies.”
An analysis of the babies’ facial movements was made using American psychologist Paul Ekman’s Facial Action Encoding System, which allowed researchers to characterize the expressions linked to laughing and crying.
Rui Diogo, a specialist in facial muscles in the anthropology department at George Washington University in Washington, D.C. says the expression of a smile remains the essence of man because among the six pairs of muscles that produce a smile, that of the risorius, which pulls the corner of the mouth outwards, is specific to human beings.
parentalcentral.ca has also added some very interesting 4-D images of babies’ facial muscle movements in utero that support these research findings.
Like crying, smiling is a primary way of establishing a link with one’s surroundings and could be a vital element retained by evolution so that a baby can form attachments with those around him or her.
Reissland would like to do a postnatal follow-up to see how the baby’s development matches the facial development in utero and whether that extra attachment in the last trimester helps the parents’ attachment and anxiety levels.
What are your thoughts on laughter and smiling as inherent human qualities?
Do you think having these characteristics as innate responses is a beneficial evolutionary trait or is insignificant?