3 ms·

I think it is hard to imagine that evolution did not result in some hard-wiring of our reactions to the sight of blood. Blood=violence, LOOK OUT!

• yorwba 7y ago
  Except for the half of humanity who bleed regularly without any violence to look out for.
  • Iv 7y ago
    Surprisingly, there indeed seems to be no hard-wired understanding of periods. Freaking out on your first one is common for unwarned young women. Dealing with this has been off-loaded to culture. And the various idiocies in traditional cultures about how to deal with menstruating women show that freaking out about this has been pretty common through history.
• cbanek 7y ago
  Well, red in nature doesn't always need to mean blood. It can also be a signal to other animals, even if they don't have red blood. Red is pretty hard to camouflage in nature, and it really stands out. Sometimes it's for attracting, such as red apples, fruit/berries, or flowers. By attracting other animals, it helps the signaler. Sometimes it's to signal danger, as in red poisonous mushrooms, or animals that have red bodies and are toxic or don't taste good. ("don't eat me") I guess what I'm saying is that red was a signal long before humans came on the scene, and I think we are still on the look out for it because of those same evolutionary clues.
  • Iv 7y ago
    False positives are not a big deal for this trait. False negatives are. A spat of blood may not mean danger, but if it systematically put you on your guards, you are likely to get an advantages over individuals who are oblivious to it.
• morningseagulls 7y ago
  >Blood=violence, LOOK OUT! Not necessarily violence, as yorwba pointed out, but the presence of some disruption or injury in the body that's producing the blood.