Sociologist who studied average outcomes, successes and failures. Also, an independent person not personally invested in making oneself sound as awesome. Also, someone not having personal interest in changing how other people act for own benefit.
Obvious example: If 10 people takes same risk and 9 of them ends up super poor and 1 super rich, then the risk taking philosophy wrote by the 1 will be significantly different then the one that takes into account also those where risk part happened.
I assume people who believe wealth and success of individuals can be explained by predictable qualities or behaviors of that person have simply never met a rich person in their life.
And you don't believe a "winning group" would hold its own biases?