Abstract
A paper-and-pencil Piagetian water-level task was administered to 250 undergraduate students within 5 college majors: engineering, natural sciences, social sciences, business, and language arts. Analysis showed significant differences between sexes and college majors. Men were significantly more accurate than women within each college major, and science majors were more accurate than liberal arts majors within each sex. Caution against treating college students as a homogeneous population in research using a water-level task is suggested.