The theory for not asking such questions is that none of them have any
intrinsic causal effect on workplace performance. We all know people
whose performance is wanting that are of a certain Race, Color, Sex,
Religion, National origin, Birthplace, Age, Disability, or
Marital/family status. However, that certain level of performance is not
common amongst ALL people of a certain Race, Color, Sex, Religion,
National origin, Birthplace, Age, Disability, or Marital/family status,
leaving the actual performance as a function of the individual, not the
arbitrary group they have been assigned to.
(By arbitrary I do not mean capricious, only that with different
thinking, different groups might have been identified, e.g., Lives Near
Water, Green Eyes, Wears Laced Shoes or Wrinkled Shirt, Has Gravel for
Front Lawn, or Shoots Left Handed.)