Dr. M’s SPA Newsletter Volume 16 Issue 13 – Birth Order

Birth Order Birth Order Is Biology, Not Birthright - so says a new paper in MedRxIV (Kramer et. al. 2026) Here is a short field guide to how sequence shapes the immune system, and maybe the brain in children. We’ve treated birth order like personality trivia. First-borns are “responsible.” Youngest are “free spirits.” Middle children… well, we forgot them. This paper suggests something more…