The saying “the more, the merrier” may not exactly hold true for families.
According to a study carried out by researchers at the University of Houston, having lots of siblings puts a child at greater risk of behavioral problems and cognitive issues.
Their findings suggest that increases in family size decrease parental investment and in turn, decreases childhood performance on measures of social behavior as well as cognitive tests. The researchers also found that these negative impacts persist throughout childhood.
“A lot of what happens in early childhood has lasting impacts. In many respects, this matters more than a lot of things that happen later in (a child’s) life,” Dr Chinhui Juhn, a co-author of the study said.
In order to come up with the results, the researchers utilized a dataset that tracked outcomes throughout childhood. Data of outcomes of older children prior and after a younger sibling was born were compared.
Having additional children suggests reduced parental investment, which is defined as “including time spent with children, affection, the safety of the home environment and resources, such as money, books, and other material goods.” However, the researchers also found that these findings may not be applicable for children coming from families with ample resources.
“If you are in a well-resourced family, some of these things don’t apply. When the second child comes along, there is less time and attention. But in an environment with more resources, it’s not as binding,” Dr. Juhn explained.