3 ms·

Or athletically minded parents tend to have children on certain months. Correlation is not causation.

• npunt 10y ago
  Both arguments are not equally plausible though. The argument for the compounding effects of physical advantage relative to peers is a lot stronger than the supposition that parents would happen to have children on certain months.
  • ec109685 10y ago
    Unless you conduct a study where you divide peer groups blindly and send some early and send some later, it is just a (educated) guess this is the reason. Otherwise, you can just walk trough data sets until you find one that meets your conclusion.
• dba7dba 10y ago
  Here's the article about higher percentage of NHL players having earlier birthdays. https://www.nhl.com/news/study-suggests-nhl-has-bias-in-favour-of-players-born-earlier-in-the-year/c-657724 https://www.nhl.com/news/study-suggests-nhl-has-bias-in-favo...