Stability in temperament and emotional expression in 1- to 3-year-old children

I examined the stability of emotional expression in 18 toddlers aged 1 year, 2 years, and 3 years using laboratory observation. The children were presented with 5 social stimuli. Their emotional expressions were video recorded and later behaviorally coded by 2 independent raters. Average latency, intensity, and duration scores for emotional expression for each child were calculated at ages 1, 2, and 3 years and compared using Friedman’s test. Intensity of emotional expression in the children showed stability over the 3 years; no significant differences were found between ages 1, 2, and 3 (χ²(2) = 1.78, p = .41). Additionally, based on parental questionnaires for each year, from 1 to 3 years of age intensity, mood, activity, approach, and adaptability were 5 dimensions of temperament that showed stability.