Dumber by the Dozen

Here’s a good reason to limit yourself to one child: His/her sibling(s) will not be as intelligent.

This is the kind of theory that has been around for years. Robert Zajonc, a social psychologist, is famous in many fields for his birth order theory of intelligence. Benefiting from their parents’ exclusivity, firstborns interact with adults more than any subsequent offspring. Until a sibling comes along, firstborns grow in a highly intellectual family environment. Secondborns, on the other hand, interact more with their sibling than their parents and so forth.

This theory is obviously debated. But today, a Norwegian study confirmed that firstborns are indeed smarter. In fact, firstborns’ IQ is on average 2.3 points higher than their younger siblings. Like Zajonc, Dr. Petter Kristensen of the National Institute of Occupational Health in Oslo attributes this difference to social rank (and not genetics). Firstborns enjoy the undivided attention of their parents and do not have to share the family resources.

When I cited Zajonc as a reason why I did not want more than one child (if at all), my gynecologist laughed it off. Who’s laughing now, doctor!?!