Competence in systems thinking is implicitly assumed among the population of engineers and managers - in fact, most technical people will self-identify as systems thinkers. But systems thinking competencies are not as prevalent as these assertions might lead one to assume. Controlled experiments show that systems thinking performance, even among highly educated people, is poor. This paper provides a set of systems thinking competencies and demonstrates how these are not as common as advertised. We also discuss how these competencies can be measured. Our main thesis is that systems thinking is not a natural act because evolution has favored mechanisms tuned to dealing with immediate surface features of problems. We discuss the implications of this philosophy and provide recommendations for closing the gap between the demand and supply of systems thinking.