Although temperament is presumed to be largely inborn, there is clear evidence that it is affected by the environment. Some of the temperament dimensions listed by both Thomas and Chess and Rothbart are highly influenced by parental behavior, particularly the dimensions related to positive and negative emotion. Moreover, even genetically based traits can be strongly influenced by the environment. Therefore, how parents, family, and the general community respond to a certain temperament in a child can modify the expression of that temperament.

For example, highly anxious and fussy children are more vulnerable to developing anxiety disorders and depression. If such children are gently encouraged to expand their tolerance for social stimulation, they can avoid disabling social anxiety. While they will probably never become gregarious extroverts, they can still develop social competence. Likewise, extroverted and sensation seeking children are vulnerable to disorders of impulsivity, such as substance abuse and aggressive and/or illegal behavior. With appropriate guidance and limit setting, however, such children can learn to effectively control their impulses.