The Australian school year starts in January (because their seasons are upside-down), so kids born in that month are almost a full year older than the December-born kids who join a team in the same year of high school. Because kids grow like crazy, the ones who are just a little older tend to crush their slightly younger opposition. It's enough of an effect that, by the end of schooling, graduating sports stars are toned, athletic, January-born supersoldiers, while their December-born classmates are broken shells of human beings who turn to accounting or Internet comedy writing.
Someone has to keep Wild Turkey in business.
The bad luck doesn't end there for those born on the wrong side of summer. A recent Michigan State University study shows that the youngest kids in a class are 60 percent more likely to be diagnosed with ADHD than their older peers. It's not due to brain injuries suffered by being held head-first in a toilet bowl by older jocks -- quite simply, the youngest kids are less mature than their older classmates, and some pediatricians make the mistake of diagnosing kids based on their grade at school rather than their age.