Under stress, newborn babies show greater brain response to pain. When newborn babies are under stress, their brains show a heightened response to pain, a new study has found. However, you'd never know it from the way those infants act. The findings show that stress leads to an apparent disconnect between babies' brain activity and their behavior. Stressed babies may not seem to respond to pain, even as their brain is still processing it. Source 1x.
Every one responds to pain but some times that pain response is slow to react. From the time you are born to the time you die pain is something we all try to avoid but it still seems to find us.