The Pair O' Dice Casino declines to hire female bouncers on the grounds that they are insufficiently strong and intimidating sufficient to effectively perform the job. During their trial for gender discrimination brought by a group of women deprived of jobs as bouncers at the casino the general manager defended the policy as well as offered as the only evidence of the policy's soundness that he, and everyone else in the world can tell, by looking, that the physical competence of women is less than that of men. What kind of defence is the general manager asserting and will it be successful?