Temperament can affect attachment in either a negative or positive way, depending on the temperamental match between the infant and adult, whether parent or infant-care teacher. Temperament is built in and can be detected early in a child’s life. Genetically determined, temperament becomes obvious as infants show differing levels of activity, emotionality, and sociability that tend to remain the same over time. Thomas, Chess, and Birch (1963), the pioneers in temperament research, categorize babies as “easy,” “slow to warm,” and “difficult.” Their work helps today’s parents and caregivers understand how temperament affects behavior and shapes personality. J. Ronald Lally and his colleagues in the WestEd Program for Infant–Toddler Caregivers renamed the categories “fearful,” “flexible,” and “feisty,” which puts them in a more objective light. A good match between parent temperament and child temperament promotes attachment; a mismatch may hinder it. If the two aren’t a natural fit, the adult must adjust to the baby rather than expecting the reverse. This is important for you to understand—both when considering your own attachment process with the children you work with and also when working with parents. You can be the one to help a parent understand temperament if a mismatch is getting in the way of attachment between parent and child.

What would a mismatch look like? If an active and intense mother with a high energy level finds herself with a slow, calm, mild baby, she may be disappointed. She may even wonder whether something is wrong with her baby, even though the baby is perfectly fine. If this high-energy mother is not aware of what she is doing, she may overstimulate her baby. She has to learn to read the signs that the baby has had enough. You can help her do that. Some parents keep on after the baby turns away or closes his or her eyes. A serious mismatch occurs when the mother interprets this behavior as bored and continues to try to “wake the baby up and make her more lively.”

Or imagine a calm, relaxed father who loves things done on schedule and appreciates predictability in his life. He’ll find a mismatch with a highly active, intense baby who never seems able to regulate his rhythms or body needs. Some babies don’t keep any sort of routine, even eating at a different time every day. Napping is as unpredictable as appetite and never follows a schedule. If the father of such a baby doesn’t accept that his son is different from himself, he may have trouble being sensitive to the child’s needs.

Parents who have children whose temperaments don’t match their own have to adjust their expectations, accept their babies as is, and learn to understand them. They have to be flexible about how and when they respond. They have to be supersensitive so that they can meet their baby’s needs. All that may be hard for a parent whose temperament isn’t flexible or sensitive. That may be hard for you too, but hopefully understanding more about temperament will help you.