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What is temperament?

Your baby has her own characteristics and patterns of behaviour that influence the way she responds to daily events in her life. This is called her temperament; it will help to shape your baby’s world and yours, too. Temperament is your baby's or child’s behavioural style. It determines how she reacts to situations, and how she expresses and regulates her emotions.

What are the characteristics of temperament?

In the 1960s, some psychologists in New York started the largest study of temperament ever conducted. It ran for three decades and assessed 131 babies from the age of three months until adulthood. At the end of the study, the researchers proposed the following nine characteristics of temperament:

  • Activity level: how active the baby is
  • Rhythmicity: how regular the baby’s sleep/wake and feeding routines are
  • Distractibility: how easily the baby can be distracted from something she is doing
  • Approach/withdrawal: how the baby responds to new experiences
  • Adaptability: how the baby adapts to new situations
  • Attention span/persistence: how persistent the baby is when faced with challenges
  • Intensity of reaction: how intense the baby’s responses and emotions are
  • Sensitivity: how sensitive the baby is to flavours, textures, and noises
  • Quality of mood: whether the baby has a happy, positive mood most of the time or an unpleasant, negative mood most of the time

The characteristics of a baby’s temperament emerge very early in life, and they become more stable as the baby gets older.

What are the major types of temperament?

As a result of the study, the psychologists determined that there are three major types of temperament: easy, difficult, and slow-to-warm-up.

About 40% of babies and children have an easy temperament, meaning that they readily approach and easily adapt to new situations, they react mildly to things, they are regular in their sleep/wake and eating routines, and they have a positive overall mood. Easy babies make their parents feel as if they are doing a great job.

Approximately 10% of babies and children have a difficult temperament, which means that they withdraw from or are slow to adapt to new situations, they have intense reactions, they have irregular routines, and they have a negative mood. They tend to have long and frequent crying episodes. Parents of difficult babies may question their child care abilities and wonder what they are doing wrong.

The term “difficult” has a negative connotation as it overlooks what are often valuable behavioural traits: assertiveness, persistence and decisiveness. Other words such as “spirited” or “feisty” have been suggested because they sound more positive; however, the word “difficult” is used here because it is the established term in the scientific literature.

Between 5% and 15% of babies and children are slow-to-warm-up, in that they withdraw from or are slow to adapt to new things, they have a low level of activity, and they show a lot of negative mood. Slow-to-warm-up babies do not like to be pushed into things. They are frequently thought of as shy or sensitive.

About 40% of children do not fit into any one category; instead, they have a combination of these qualities.

How do the characteristics and types of temperament relate to each other?

Because many babies and children do not fit into a particular category, it is sometimes helpful to consider how the characteristics and types of temperament relate to each other. A baby may have some “difficult” characteristics and other characteristics that are “easy.” For example, your baby might have intense reactions and yet be very regular in her sleep/wake and feeding routine. The relationship between the characteristics and types of temperament are summarized in the table below:

 Types of Temperament

 Temperament characteristic

 Type of temperament




 Activity level


 Low to moderate



 Very regular








 Approaches readily

 Withdraws at first



 Very adaptable

 Slowly adaptable

 Slowly adaptable

 Attention span/persistence

 High or low

 High or low

 High or low

 Intensity of reaction

 Low or mild




 High or low

 High or low

 High or low

 Quality of mood


 Slightly negative


Source: Thomas A, Chess S, Birch AG. The Origin of Personality. Scientific American 1970;223:102-9.

What is goodness of fit?

Goodness of fit is a term to describe how well a baby’s temperament fits with the expectations and demands of the baby’s environment. Since primary caregivers have the most influence within a baby’s world on a day-to-day basis, it is the expectations and reactions of the parents that will contribute most to a good or poor fit. This fit between parent and child becomes increasingly important as the baby gets older and develops into his personality. A laid-back or low-energy parent may have difficulty dealing with a child who is very active and intense; this is an example of a poor fit between parent and child. On the other hand, a laid-back parent might appreciate and admire the intensity and focus that a difficult child portrays; this is goodness of fit.

Your baby is relying on you to build the best fit that you can for the both of you. A good fit between you and your baby can be a joy, but it may be challenging to achieve at times. A number of factors may shape the expectations that you have for your baby, including your own temperament and past experiences with your own parents. For example, an adult raised by an anxious or depressed parent may feel frustrated or challenged by a slow-to-warm up baby who reacts tentatively to new people and environments. In this case, she may expect more positive reactions from her baby because her child’s reactions serve as uncomfortable reminders of her own childhood and she fears that history will repeat itself.

When there is a mismatch between a parent’s expectations and a child’s temperament, a negative cycle can emerge that can be difficult to break. For example, if expectations do not match a child’s temperament, a parent’s reactions can exaggerate a child’s behavioural and emotional difficulties, leading to a deterioration in parent-child interactions. In severe cases, parents may require professional guidance to develop a better fit with their child. However, other parents may benefit from reflecting on their own emotions and behavioral characteristics and thinking about how their expectations might be affecting their child’s reactions.

If you consider these issues in your own case, remember that goodness of fit can extend beyond your immediate relationship with your baby. For example, if your baby attends care outside of your home for part of the day, it will be important to consider how well the environment accommodates your baby’s emotional and behavioural characteristics. For example, a baby who is slow to adapt to changes and who is responsive to even small amounts of stimulation would likely benefit from care that is structured with predictable routines and from an environment that is not too busy or noisy.

Brenda S. Miles, PhD, CPsych