The researchers at Auburn University and the Catholic University of America claim that the children, who often witnessed family scenes at the age of 8 years, demonstrated a lower adaptive response at the age of nine. The scientists studied the state of 251 children from nuclear families. The children talked about their participation in family conflicts when they were 8 years old, about their frequency, the extent and intensity of emotions as well as lack of reconciliation between the parents.
The scientists have recorded the performance of the children’s system of stress response by measuring the level of respiratory sinus arrhythmia, when the heart rate increased at breathing in and slowed down when breathing out. Arrhythmia of this kind was associated with the ability to regulate attention and emotions. The ability to quickly find and solve problems, differentiating new information, was measured in the participants of the study aged 8, 9 and 10 years old.
The children, who often witnessed the scenes of family quarrels at the age of 8 years, showed a lower adaptive response at the age of 9 years. The children, whose stress response system demonstrated low performance, also had slower intellectual development.
The findings give evidence that stress affects the system of responding to stressful situations, which helps control attention. According to Dr. Benjamin Hinnant, associate professor of psychology at the Catholic University, the way the system works is connected with the development of cognitive abilities.