Picking favorites with your kids is bad for everyone, according to a new study.
Researchers in Canada say that the entire household dynamic is disturbed when parents treat one child differently than the other.
“It’s not just about individual favoring or disfavoring," said lead researcher Jennifer Jenkins, according to Global News.
"It’s about a family dynamic that occurs and shapes the whole family."
The study looked at 400 families in Canada with children between the ages of two and five over four years, said Time.
They interviewed the parents about their children and watched the families interact in their homes.
More from GlobalPost: One fifth of British parents think alcohol improves their parenting skills
Although no parents said they favored one child over another, researchers used observed behavior to make the determination, said ABC News.
Researchers said that treating one child differently from another is not necessarily intentional - some parents simply get along with one child better than the others.
They found that even the more positive treatment of one child has negative consequences like mental health problems.
Researchers put it down to feelings of unfairness and a lack of equity.
“It’s experiencing divisiveness in the family. Even though they’re favored, there’s this sense of some unfairness. It’s uneasiness and it doesn’t foster good sibling relationships,” Jenkins told Global News.
Those parents who treated one child better than another typically had more stressful situations like being a single parent.
The study was published in the journal Child Development.