Facial Expressions Unveiled
News Medical. Net just reported on research by Rebecca Riddell and colleagues suggesting that a single stereotyped pain expression during infancy does not exist. The authors say that each facial expression is attached to a different type of distress.
They found 7 distinct facial expressions after vaccinations on infants from 2 months to 12 months, which could signal different types of pain and aid communication of distress to caregivers.
“We propose that these seven categories of expressions may have evolved to allow infants to communicate two crucial broad states to caregivers: level of distress and degree of regulation from distress,” write Riddell et al.
The researchers categorized babies’ facial expressions using the Facial Action Coding System for Infants and Young Children (BabyFACS). According to this system, the authors found that the expression of the Red facial type (defined as cry, accompanied by oblique eyebrows) within 1 minute of a vaccination varied significantly according to age. For example, 7.49% of 2-month-old babies showed the Red facial expression compared with 5.12% of 4-month olds, 9.51% of 6-month olds, and 18.87% of 12-month olds.
The Green facial type (horizontal mouth, closed eyes) changed significantly with age, with 2.49% of 2-month olds expressing it compared with 2.40% of 4-month olds, 2.51% of 6-month olds, and 0.00% of 12-month olds.
A quick note on a similar topic: The Times of India has reported that the gene which determines human facial expressions has been identified. Researchers used MRI scans to identify 5 genes that determine human facial expressions.
“These are exciting first results that mark the beginning of the genetic understanding of human facial morphology…Perhaps some time it will be possible to draw a phantom portrait of a person solely from his or her DNA left behind, which provides interesting applications such as in forensics. We already can predict from DNA certain eye and hair colors with quite high accuracies,” said Professor Manfred Kayser from the Erasmus University Medical Center, Rotterdam, The Netherlands.