Douglas A Granger of Pennsylvania State University and other scientists have found out that a little saliva can tell how you feel .
This was revealed after four independent studies released this month found that a simple test of an infant's saliva can determine the level of alpha amylase, an enzyme secreted by the salivary glands that has been linked in previous studies in adults to the sympathetic nervous system's 'fight or flight' response to stress.
Douglas A Granger of Pennsylvania State University, the lead author of the four team studies, said, ''The unique part of what we did was applied this measurement (for alpha amylase) to determine whether it was stress-responsive in children, which had not been done before. We think that these differences could prove to be meaningful in understanding behaviour."
Preschoolers, school-age children and teens were also studied along with mothers and their infants.
Collection methods of saliva are various like from using a cotton swab on a baby to having a teen drool into a straw. It is frozen and sent to a laboratory for evaluation.
"Mothers and their 6-month-old baby boys were "attuned" and had similar alpha amylase levels. The studies found that 4-year-olds with higher alpha amylase levels were more susceptible to illness and had less close relationships with their preschool teachers. The associations between alpha amylase and illness were somewhat stronger for girls than for boys", said Dr. Granger
These new studies can be found as a paper, ''Integrating the Measurement of Salivary Alpha-Amylase into Studies of Child Health, Development and Social Relationships'', published in the Journal of Social and Personal Relationships in April.