(NaturalNews) When parents play favorites among their children, it's not just the less-favored child who develops mental health problems, according to a study conducted by researchers from the University of Toronto, McMaster University, the University of Rochester and published in the journal Child Development. Instead, the entire family's mental health is affected.
"This was really surprising," lead author Jenny Jenkins said. "We expected differential parenting to operate stronger within the parent-child dynamic. However, differential parenting had a stronger effect on the entire family."
The researchers followed 400 Canadian families, each of them with between two and four children of average age two to five. Unlike prior studies on differential parenting, which have focused mostly on families with two children, the current study was able to examine wider family dynamics. Using information from mothers' reports and observations by the researchers, parenting was ranked as more or less "differential," meaning whether one child was favored over others.
The researchers found, as expected, that children whose siblings were favored over them ended up with more mental health problems over time than the siblings who got better treatment. But they also found that every child in a differential parenting household ended up with more mental health problems than children from households where their parents treated them equally.
Mental health problems particularly included attention problems and trouble with social relationship.
"In all likelihood, this occurred because differential parenting sets up a dynamic that is very divisive," Jenkins said.
"Sibling divisiveness is a known result of differential parenting, with lasting effects into adolescence and adulthood."
Environmental risk factors
The researchers also analyzed the riskiness of each mother's situation, including factors such as single parenting, low income and a history of abuse. They found that the more risk factors a mother experienced, the more likely she was to practice favoritism among her children. All the risk factors studied have also been correlated with higher rates of mental health problems in children.
"Parents don't set out to be horrible to one child versus another," Jenkins said. "There are many environmental factors that lead parents to these actions."
"As parents, we have to be aware of these factors, and not let them affect our parenting."
Pediatric specialist Rahl Briggs of Albert Einstein College of Medicine, who was not involved in the study, said that society should do more to help parents in such risky situations.
"While all parents know that it's best to avoid comparing siblings to each other, and to strive for equity in terms of attention, optimal parenting of this sort is incredibly difficult when faced with multiple risk factors, such as poverty, mental illness, and a history of adverse childhood experiences," Briggs said.
"[The study] further supports the claim that we must support families, especially those families with young children, to help ameliorate some of these impacts of risk," he said.
"The experiences of young children create a foundation upon which future development and behavior is built, and it's really imperative that this foundation be strong."