Older Children not Smarter Than Their Younger Sibs
Siblings and Intelligence
A recent study provides some of the best evidence to date that birth order really doesn't have an effect on intelligence.
The findings contradict many studies over the years that had reported that older children are generally smarter than their younger siblings.
This new study, based on a large, nationwide sample, suggests a critical flaw in that previous research, said Aaron Wichman, lead author of the new study and a teaching fellow in psychology at Ohio State University.
Most previous studies compared children from different families, so what they were finding were differences between large and small families, not differences between siblings, according to Wichman.
"Third- and fourth-born children all come from larger families, and larger families have disadvantages that will impact children's intelligence," he said.
"In reality, if you look at these larger families, the fourth-born child is just as intelligent as the first-born. But they all don't do as well as children from a smaller family."
Wichman conducted the study with Joseph Lee Rodgers of the University of Oklahoma and Robert MacCallum of the University of North Carolina