Corbett refuses to take reasonable precautions to protect his health because he believes good health is just a matter of luck anyway. corbett's attitude best illustrates:

I believe the answer is: an external locus of control

an external locus of control refers to the belief that every outcome that happens in our life are caused by something that couldn't be controlled by us individually,.

In general, people with an external locus of control would be much less likely to achieve success and good general well being in their life.