Many of the apparent differences between firstborn and later-born children are really due to differences between small and large families.

Question

Many of the apparent differences between firstborn and later-born children are really due to differences between small and large families.​

Quizplus · Accepted Answer

Studies have shown that birth order effects are often confounded with family size. Children from smaller families tend to have better educational outcomes, fewer behavioral problems, and higher IQ scores compared to those from larger families. However, when family size is controlled for, some birth order effects still remain, although they tend to be small in magnitude.

Many of the Apparent Differences Between Firstborn and Later-Born Children