Are The Oldest Children The Smartest?

“The new evidence that eldest children develop higher I.Q.’s than their siblings has intensified the debate over two of the most stubborn questions in social science: What are the family dynamics that enhance intelligence? And can they — and should they — be changed?

“The new findings, from a landmark study published Friday, showed that eldest children had a slight but significant edge in I.Q. — an average of three points over the closest sibling. And it found that the difference was not because of biological factors but the psychological interplay of parents and children.

“Psychologists say that filling the role of the responsible firstborn, while important to academic achievement, still does not account for eldest children’s higher average scores on intelligence tests. Robert Zajonc, a psychologist at Stanford University, has argued that in fact having a younger sibling or two diminishes the overall intellectual environment for eldest children — who otherwise would be benefiting from the rich vocabulary and undivided attention of parents.

TheStateOf . . . Kids. I (J) felt like having an older brother was a huge advantage for me - and still is. But maybe it worked to improve my brother’s IQ because he had to figure a lot of things out on his own. Whereas, I was told a lot of things.