Describe the development of aggression, including individual differences in aggressive behavior

What will be an ideal response?

In the second half of the first year, infants develop the cognitive capacity to identify sources of anger and frustration and the motor skills to lash out at them. By the second year, aggressive acts with two distinct purposes emerge. Initially, the most common is proactive (or instrumental) aggression, in which children act to fulfill a need or desire—obtain an object, privilege, space, or social reward, such as adult attention or (in older children) peer admiration—and unemotionally attack a person to achieve their goal. The other type, reactive (or hostile) aggression, is an angry, defensive response to a provocation or a blocked goal and is meant to hurt another person.
Proactive and reactive regression come in three forms, which are the focus of the majority of research:
1. Physical aggression harms others through physical injury—pushing, hitting, kicking, or punching others, or destroying another's property.
2. Verbal aggression harms others through threats of physical aggression, name-calling, or hostile teasing.
3. Relational aggression damages another's peer relationships through social exclusion, malicious gossip, or friendship manipulation.
Between ages 3 and 6, physical aggression decreases, whereas verbal aggression increases. Rapid language development contributes to this change, but it is also due to adults' and peers' strong negative reactions to physical attacks. Furthermore, proactive aggression declines as preschoolers' improved capacity to delay gratification enables them to resist grabbing others' possessions. But reactive aggression in verbal and relational forms tends to rise over early and middle childhood. Older children are better able to detect malicious intentions and, as a result, more often respond in hostile ways.
Beginning in the preschool years, girls concentrate most of their aggressive acts in the relational category. Boys inflict harm in more variable ways and, therefore, display overall rates of aggression that are much higher than girls'. At the same time, girls more often use indirect relational tactics that—in disrupting intimate bonds especially important to girls—can be particularly mean. Whereas physical attacks are usually brief, acts of indirect relational aggression may extend for hours, weeks, or even months. In adolescence, the gender gap in physical aggression widens. Although girls account for about one in five adolescent arrests for violence, their offenses are largely limited to simple assault (such as pushing and spitting), the least serious category. Serious violent crime, however, continues to be mostly the domain of boys. SES and ethnicity are strong predictors of arrests but only mildly related to teenagers' self-reports of antisocial acts.