This study was conducted just in B.C., which opens the door for the possibility of regional/seasonal effects. What if being born earlier in the year means that

This study was conducted just in B.C., which opens the door for the possibility of regional/seasonal effects. What if being born earlier in the year means that you spend more of a critical early-development window in a structured environment (e.g. preschool, kindergarten, etc.), which permanently affects how your brain is wired?