"Easy", "difficult", and "slow-to-warm-up"
Thomas, Chess, Birch, Hertzig and Korn found that many babies could be categorized into one of three groups: easy, difficult, and slow-to-warm-up (Thomas & Chess 1977). Not all children can be placed in one of these groups. Approximately 65% of children fit one of the patterns. Of the 65%, 40% fit the easy pattern, 10% fell into the difficult pattern, and 15% were slow to warm up. Each category has its own strength and weakness and one is not superior to another.
Thomas, Chess, Birch, Hertzig and Korn showed that Easy babies readily adapt to new experiences, generally display positive moods and emotions and also have normal eating and sleeping patterns. Difficult babies tend to be very emotional, irritable and fussy, and cry a lot. They also tend to have irregular eating and sleeping patterns. Slow-to-warm-up babies have a low activity level, and tend to withdraw from new situations and people. They are slow to adapt to new experiences, but accept them after repeated exposure.
Thomas, Chess, Birch, Hertzig and Korn found that these broad patterns of temperamental qualities are remarkably stable through childhood. These traits are also found in children across all cultures.
Thomas and Chess also studied temperament and environment. One sample consisted of white middle-class families with high educational status and the other was of Puerto Rican working-class families. They found several differences. Among those were:
- Parents of middle class children were more likely to report behavior problems before the age of nine and the children had sleep problems. This may be because children start preschool between the ages of three and four. Puerto Rican children under the age of five showed rare signs of sleep problems, however, sleep problems became more common at the age of six.
- Middle class parents also placed great stress on the child’s early development, believing that problems in early ages were indicative of later problems in psychological development, whereas Puerto Rican parents felt their children would outgrow any problems.
- At the age of nine, the report of new problems dropped for middle class children but they rose in Puerto Rican children, possibly due to the demands of school.
Read more about this topic: Temperament