Personality questionnaires are particularly useful to gauge a candidate’s likely level of fit for a role or team. They measure relatively stable behavioural tendencies and work style preferences. Personality questionnaires are well-established useful tools to support hiring decisions.
Personality questionnaires can be used to assess how a candidate is likely to handle work-related tasks such as managing stakeholders, working in teams, complying with rules and regulations, leading others, coping with stress and pressure etc.
Personality questionnaires do not measure what the candidate has the ability to do, but rather how they prefer to behave in the workplace. Personality influences performance because people are usually more motivated in a role if they are doing something they prefer doing. That is, people enjoy work environments that allow them to be themselves.
If a candidate’s personality profile is not aligned to a particular role, this does not mean they cannot do the job: many people learn to manage their natural tendencies to perform effectively at work. However, working in a role that requires behaviour that does not come naturally (e.g. a reserved person in a sales role) tends to be less rewarding and enjoyable, and increases the likelihood that a person will leave the organisation.