By definition, a person’s personality is “the combination of characteristics or qualities that form an individual’s distinctive character.” Personality tests attempt to define this character, by asking questions about a person’s behavior, values, interests, and attitudes. By design, the tests are self-reporting, leaving the results largely subject to personal bias. They are influenced by the test-taker’s interpretation of the questions, views of themselves (or how they would like to see themselves), and their assumptions about how other people experience them.
In addition, it is basic human nature to want to see ourselves as culturally acceptable and in alignment with the values and ideals of our community. When answering a question that gauges empathy, a test taker may “fake” the answer, assuming the empathy is a valued attribute.
In employment situations, bias is even more evident. Test-takers will often select the answer they believe the employer is looking for. Their responses are influenced by the desired outcome, such as getting hired, a promotion, or simply looking good in front of a boss. This could mean they are recruited into a position that isn’t suitable to who they really are.