This chapter is about emotional development and temperament, focusing on three topic areas: individual differences in temperament, emotional reactivity and regulation, and emotional understanding and empathy. Do we all express emotions similarly across cultural communities?Paul Ekman found that there is a universality to emotional understanding and expressions, and babies exhibit tase basic emotional expressions as well. How does temperament differ from emotions? Emotions cary through the course of a day, while temperament is a predisposition toward reacting to emotional experiences that is stable over time and thought that people may be predisposed to. Thomas and Chess looked at individual differences in infants’ emotional responses to their environment to comprise a baby’s temperament, rating babies on activity level, temperament, body functions, and behavior, as well as adaptability, approach to new situations, threshold of reactivity intensity, and distractibility. There are four profiles of baby: easy babies, difficult babies, slow to warm up babies, and average babies, and these temperaments predicted the big five personality type of extraversion, agreeableness, neuroticism, openness, and conscientiousness. These differ in different cultural contexts and communities. Parents’ use of emotion language is important to help babies recognize and identify emotions.