Every parent has to deal with that dreaded time known as "the terrible twos." It is a period where all kids test boundaries and try to become more independent -- which can result in testing the limits of mom and dad's patience.
However, our recent study shows that in the period leading up to toddlerhood, how parents deal with this growing independence can determine how much children will act out as they get older. During the challenging time period (from nine months to age two), children are testing their limits, while parents are starting to have higher expectations for their children's behaviour.
This creates some tensions, and most parents experience stress and frustration. But when parents over-reacted -- for example raising their voices or yelling frequently -- to their children's negative behavior, their children were more likely to become more badly behaved as they approached age two.
How parents and children adapt to this challenging time is important to a child's development. Many children experience more "negative emotionality" (being fussy, easily upset, difficult to soothe) during this time, but those that increase the most also tend to "act out" more as two year olds. And those with the biggest increases in problem behavior also appeared to have parents who over-reacted to their early outbursts.
These negative outbursts not only have an impact on a child's development -- they can also hurt parents. In a prior study, we found that parents of children who increase a lot in negative emotionality during toddlerhood also tend to become more over-reactive when responding to their children. They also became less confident in their parenting abilities.
Although it is important to set and enforce limits with your children, parents should do their best to keep their own emotions and stresses in check when children test those limits. When we as parents can manage our own emotions, even when children are testing limits, we help them learn to control their behaviour in more appropriate ways. This can have a positive impact later when they are in school.
Our new study, just published in the journal Development and Psychopathology and funded by the National Institutes of Health, looked at data from 361 families linked through adoption (including birth parents and adoptive families) in 10 different states in the United States. By analyzing data about children's genetic risks for negative emotions in addition to data on parenting and child development, we were able to isolate the effect of parenting, separate from shared genetic background. Genetics played a role, but only for children that did not have over-reactive parents. While genetics can be important in the development of children's problem behaviors, it appears the strongest and most consistent effects on children's behavior come from parenting and the home environment.
Overall, research on early childhood development shows that the things parents enjoy doing with their children, like reading and playing together, are good for a child's development. Although it is also important to set boundaries with young children -- and to stick to them -- try not to get too worked up when children act out. When parents are able to keep their cool, and find fun and positive activities to share with their children, the "terrible twos" can seem a whole lot less terrible.