When you’re knee-deep in the dating game, it’s not at all uncommon to hear the age-old question, “What’s your type?” Oftentimes the answers to this question feel a touch surface-level; you might say ...

Ask a person of a certain age what their blood type is, and chance are they’ll know it offhand. From military dog tags to Cold War-era tattoos on children, the idea was that knowing your blood type ...