biological differences between the sexes do not mean that boys "have" more aggression without having to acquire it: rather they have a greater readiness to learn it. It is important that the aggressive behavior of both sexes is subject to modification.
The emotions of young children are very unstable, in that children tend to react strongly to experiences that are frustrating or rewarding. Emotion is a difficult word to define. Positive emotions are characterized by "approach" behavior; fear or anxiety, by flight or avoidance; and rage responses by "against" behavior. Neonates' emotions tend to take the form of generalized excitement, although cries indicating hunger, anger, or injury may be identified. Smiling appears toward the end of the first month and reaches a peak at about five or six months of age. Laughter appears when the infant is four to six months old.
Anxiety, in the form of "sobering" when strangers are seen, is evident about the middle of the first year. A few months later, the infant begins to express anxiety when separated from his caregiver. A longitudinal study found that boys who did much crying during the early months of infancy tended to remain apprehensive in strange situations during the early childhood years, whereas those who did not cry tended to be less tense and shy. Girls displayed no such consistency over time. An early study indicated that children's fearfulness was high when they were two, but declined thereafter. In general, children scoring higher on intelligence tests displayed more fear and anxiety during the early toddler years than did those scoring low.
The sources of anxiety are less readily identified than are sources of fear, and anxiety is generally less intense than fear. Anxiety does facilitate concern about the future and stimulates socialization, but in its more severe forms it can have an immobilizing and interfering effect. An experiment with anxiety-arousing situations showed that children tended to stay close to their mothers, or another female adult in situations in which the mother was not available.
Fantasy violence appears to have a natural fascination for young children. A survey by Ames showed that about three fourths of children aged two to five spontaneously tell stories with violent themes. One study reported a negative relationship between parental punishment and aggressive themes in children's doll play, a finding which suggests that violence appears in children's fantasy spontaneously, perhaps because it is exciting and interesting.
Most of the research studies on emotions of preschoolers are concerned with anger and aggressiveness; fewer deal with fear and anxiety and even fewer with the positive emotions.