Why can employers discriminate based on intelligence but not appearance?

people have the same amount of control over respectively one, people have less control over how smart they are, and contained by some cases apearance is more important for ability to complete a job
They can also discriminate on appearance. The imperative just says the can not discriminate based on your see, sex , or national origin.There is a wide variation of both intelligence and appearance inside these groups and you can have real job requirements that may still block a members of a protected group from consideration. That is a model for clothes must not only be attractive but of the appropriate gender. Employers CAN reasonably and routinely DO discriminate on the basis of appearance. In many positions, appearance is MORE important to employment performance than intelligence. Actually, it is EXTREMELY rare to discriminate on the basis of INTELLIGENCE. You can be vastly intelligent and not know anything useful for the job. It is equally possible to know the job inside and out short being especially intelligent.
Because, deplorably, appearances, such as race, sex or sexual orientation are protected classes. And in some cases will over rule intelligence, such as contained by Affirmative action programs where there have to be a specific blend of protected classes, even if the "unprotected" class is more qualified. Someone with intelligence level of a high schooler is not going to return with a job designed for a college graduate level computer engineering job. This is not a socialist or communist society - everyone is not equal within the sense of intelligence, and, therefore, a person with high intelligence applies that intelligence to a higher paying, higher skilled position. Its for the same root that an ugly, overweight person would not get a postion as a Victoria's Secret model.
I don't devise that's true. The discrimination still occurs, it is just not as unconcealed (i.e. not being passed on for the next interview). It is not actually nouns, it is that every company has a culture, and someone can be judged by their appearance as to whether they fit in to the coprorate culture.
An employer can discriminate on the basis of both; the only piece they can't discriminate on is something in a EEOC protected class, and even then there have to be a demonstrated pattern that the employer denied employment based solely on the protected class basis and even consequently, if they are a larger company with over 50 employees total