Okay, but it's not like he just let the people into the study, gave them a questionnaire, and called it a day. He performed a battery of interviews and experiments with them which showed a consistent set of traits and habits, even going as far as to tape them doing mundane tasks like waiting in a coffee shop (which I discussed). Yes, it could be the case that the extraversion, orientation toward novelty, etc. are mere artifacts and all the lucky people were just the beneficiaries of being in the thin part of the bell curve -- but then, Dr. Wiseman also trained 'unlucky' people in these and related skills and was able to get them to improve their self-reported luck.