 However, the emotional vocabulary of children grows much more rapidly during middle childhood, doubling every two years in this period before slowing down dramatically in adolescence.At the end of the preschool period, most children reliably comprehend the meaning of around 40 emotion words; by the time they are 11 years old, most children see a sevenfold increase to understanding almost 300 emotion words.Emotional display rules are culturally bound norms that dictate when, how, and with whom individuals can express emotions.