Originally published 18 March 1996
Are people born in the spring smarter than the rest of us?
A flurry of letters in [1996] issues of the prestigious science journal Nature suggests that they are. The data are hardly scientific, but I know a marketable idea when I see one. Might as well get on the bandwagon now.
It started with letters linking birth date to success in sports. Then a British psychologist named Michael Holmes set the pot boiling by linking birth dates to scientific creativity.
Holmes looked at biographies of scientists who supported the revolutionary theories of Darwin and Einstein, and those who resisted the new theories. He found an apparently significant majority of the revolutionaries were born from December to April. The reactionaries were mostly summer babies.
Inspired by Holmes, physicians on the faculty of medicine at the University of Porto, Portugal, examined birth dates of their students, young people who were at the top of their high school classes. A tantalizing bulge in the birth dates occurs in the months April to June. The birth date distribution in the general population is more or less flat.
Next, doctors on the faculty of medicine at the University of Florence, Italy, chimed in. Ditto. More bright students born April to June.
What could be the cause of this phenomenon, assuming it is real?
Holmes argues for a seasonal effect on early development, through maternal behavior or biology, before birth or during the first year of extrauterine life. Light-induced hormone fluctuations, he suggests, might be a potent influence on early development.
The social environment of the infant might also be influenced by the seasons, Holmes guesses: “Initially, the winter-born revolutionary would have been restrictively swaddled but with the coming of summer he would have experienced more freedom to explore on his own initiative.”
The doctors in Porto and Florence look to theories of neuro-development. Unlike a computer, the brain must “wire itself,” and this process is strongly affected by external stimuli. Apparently, there are critical periods in early development when “self-wiring” takes place. The spring baby may be favored by seasonal differences in the environment, either in the womb or out.
Another letter in Nature, from faculty at the School of Medicine of the University of Rome Tor Vergata, offers evidence that the season of conception may influence intrauterine development. They specifically looked for a correlation of birth date and an enzyme that may have important functions in cellular growth regulation and in the modulation of glycolytic rate. They conclude: “The effects on neonatal parameters measurable at a general population level seem rather small, but may be far-reaching in selected groups of talented people.”
Now, don’t get me wrong, we shouldn’t take any of this too seriously. The data are sparse, and we haven’t heard yet from the southern hemisphere, where the seasons are reversed. Finding an October bump in the birth dates of smart Australians will be a crucial observation. Also, children generally start school according to birth date, and this might confer an artificial advantage on a certain age group.
Nevertheless, now is the time for someone to move on a hot new book for yuppie parents: “April’s Child: Seasonal Influences on Early Development and Success in Later Life,” or “Conceiving Einstein: Optimizing Your Child’s Intelligence and Creativity.”
There’s a best-seller here, I can smell it.
This is the sort of thing that will torment yuppies who want their offspring to have every intellectual and creative advantage. Play schools, ballet lessons, gymnastics, early school starts, and all the rest won’t be enough. Now, parents’ responsibilities to their child’s future will start with the month of conception.
And the guilt! “Oh God, Francis. I’m pregnant, and the baby will be born in August.”
The maternity wards of hospitals will be jam-packed in the spring and empty in the fall. Obstetricians will be as seasonally employed as lifeguards and hockey players.
The clustering of toddler birthday parties in a busy spring “season” will mean boom or bust for clowns, story-tellers, and magicians.
Not only will every kid in class have the same name — Ashley or Michael, or whatever is currently fashionable — they will also have the same birthday.
Couples who inadvertently conceive in the wrong season will be forced to move to Australia for the duration of the pregnancy and first year of birth, or face embarrassment at home: “Can you imagine, Ellen is giving birth in September! I mean, it’s like she doesn’t care.”
If the birth-date/intelligence phenomenon is real, and if seasonal differences are the cause, then it may turn out that certain crucial stages of neural development are influenced by ambient light or temperature. This will unleash another flurry of best-selling yuppie manuals: “Cold Smarts: How to Keep Cool During Pregnancy and Enhance Your Child’s Potential,” or “Bright Ideas: Turn Up the Lights and Help Your Infant Learn.”