Measurement of ear pulse waves in children: Effect of facing another child and relationship to an action index

We measured ear pulse waves in 38 children from a nursery school class for 5-year-olds. Ear pulse waves were measured in each child for 1 min. Two children then faced each other, and the ear pulses of both were measured. We used these biological data to examine the effect of facing another child and the relationship of this effect to an action index. The relationship between problem behavior in the children and maternal attachment was then investigated. Each mother filled out a checklist on maternal attachment and her child´s behavior. The nursery school caregiver also filled out the child behavior checklist for each child. The measured values were subjected to chaos analysis, and the Lyapunov exponents were calculated. The change in the Lyapunov exponent between the single-child and child-pair measurements is thought to relate to the maternal attachment index and the child´s action index.