Children whose parents tend to become angry easily and over-react are more likely to act out and become upset easily,say researchers.
The research is an important step in understanding the complex link between genetics and home environment.
In a study,researchers from Oregon State University,Oregon Social Learning Center,and other institutions collected data in 10 states from 361 families linked through adoption and obtained genetic data from birth parents as well as the children.
They followed the children at nine,18 and 27 months of age,and found that adoptive parents who had a tendency to over-react,for example,were quick to anger when children tested age-appropriate limits or made mistakes.
These over-reactive parents had a significant effect on their children,who exhibited negative emotionality, or acting out and having more temper tantrums than normal for their age.
Genetics also played a role,particularly in the case of children who were at genetic risk of negative emotionality from their birth mothers,but were raised in a low-stress or less-reactive environment.
This is an age where children are prone to test limits and boundaries, said lead author Shannon Lipscomb,an assistant professor of human development and family sciences at OSU-Cascades.
However,research consistently shows that children with elevated levels of negative emotionality during these early years have more difficulties with emotion regulation and tend to exhibit more problem behaviour when they are of school age, Lipscomb noted.
Researchers also found that children who exhibited the most increases in negative emotionality as they developed from infants to toddlers (from nine to 27 months of age) also had the highest levels of problem behaviours at age two,suggesting that negative emotions can have their own development process that has implications for childrens later behaviours.
This really sets our study apart. Researchers have looked at this aspect of emotionality as something fairly stable,but we have been able to show that although most kids test limits and increase in negative emotionality as they approach toddler age,the amount they increase can affect how many problem behaviours they exhibit as 2-year-olds, Lipscomb said.
Lipscomb said the take-away message for parents of young children and infants is that the way they adapt to toddlerhood,a challenging time marked by a childs increasing mobility and independence can have an impact on how their child will develop.
Parents ability to regulate themselves and to remain firm,confident and not over-react is a key way they can help their children to modify their behaviour. You set the example as a parent in your own emotions and reactions, she concluded.
The study was published in the latest edition of the journal Development and Psychopathology.