Which temperamental style results in an individual who has the most difficulty with externalizing behaviors such as aggression and conduct problems later in life?

Difficult

Explanation:

Many psychiatrists are of the notion that there are three fundamental types of temperaments and they are: easy, slow to warm up, and difficult. The difficult temperamental style is usually characterized by negative mood, not being able to adapt to new situations, irregular bodily functions, and intense reactions. People with this temperament style have great difficulty with externalizing behaviors such as conduct problems and aggression late in life.