Differential Item Functioning (DIF) is a widely used term in test development literature. It is very important to analyze test's data for DIF because It is a serious threat to validity. If the same data matrix was transposed, similar analysis can be carried for Differential Person Functioning (DPF). The purpose of this paper is to introduce and encourage the use of DPF analysis in tests of emotional or cognitive intelligence as a diagnostic approach through two examples illustrating the presence of DPF. (Contains 3 figures.)