In the past, many employers consciously or unconsciously used physical characteristic (including how an applicant looked) as criterion. Studies found that employers were more likely to hire and pay better wages to taller men, and airlines chose flight attendants and companies hired receptionists on the basis of beauty. Many times, such practices discriminated against ethnic groups, women, and handicapped people. For this reason, they are now illegal unless it can be shown that physical characteristic is directly related to effectiveness at work. For example, visual acuity would be physical characteristic that could be used to hire commercial airline pilots. It might not, however, be legally used for hiring a telephone reservation agent for an airline.