(Social) science needs participants, whether we like it or not. Without participants there is no data, and without data there is no knowledge. The reliability of our findings is inseparable from the identity of our participants and how we are able to motivate them.
Just last month NASA published a one-of-a-kind twin study, describing what physiological, molecular and cognitive changes could happen to us from exposure to spaceflight hazards. This study proves, once again, the capability of our body to adapt to extreme environments.