Smiling Is An Inherited Behavior That Begins In The Womb
British researchers discovered that the mechanism responsible for smiling develops in the intrauterine life. Scientists reached this conclusion after studying two babies, using sophisticated techniques to view the fetus in the womb.
The Study conducted at the University of Durham provides evidence that laughter and smiles are an, which is activated only in response to environmental stimuli.
In humans, facial movements occur in the first 10 weeks after birth, following that, with time, become increasingly complex.
Researchers used an ultrasound device to record two babies facial expression in their mothers wombs. Analyzing the facial movements, from the 30th week of life, specialists could identify specific expressions such as laughter and crying. Four weeks later, less than a month before birth, recognizable expressions were already easy to identify. In these circumstances, researchers stated that, when smiling, babies do not imitate a behavioral movement observed in others, it is a manifestation of an independent action which was not learned but inherited.
Although researchers now support the idea that the smile is an inherited behavior, they have not established a clear scientific explanation yet.
One potential explanation could be related to the functioning of the nervous system. Scientifically speaking, the smile is one characteristic of higher primates facial expressions. Although chimpanzees have the same number of pairs of facial muscles like the humans, 23 to be more exact, there is one key difference. Of the six pairs of muscles responsible for laughing, the risorius muscle pair, which lifts the corners of the mouth, is specific to humans.
Another theory that could that be valid claims that smile is “pre-programmed” to all people. All humans smile. Some people who suffer from mental disorders may smile or laugh for no reason, and this type of spasmodic smile appears more like a reflex than a social emotions signal. However, normally, smile is a universal expression of joy, in all cultures.
The study is also supported by Darwin’s theories. He noted that in children that are born deaf and blind, smile appears as an expression of joy and happiness and not as a product of learning.