Having conducted over three thousand interviews, mainly with accounting staff of all levels of skill from accounts clerks to CFOs, I became very used to minimising the charisma factor in an interview. From hard experience I found that the confidence a candidate displayed in an interview did not necessarily translate to performance on the job.

As I was recruiting temp account staff for most of my recruiting career, I soon discovered that clients weren't that fussed about personality types; the most important thing was placing a temp who could start working effectively from the first hour.

Well known recruitment expert Lou Adler, has written about the mistake of an interviewer being too dazzled by the four A's of charismatic candidates (articulate, attractive, ambitious and affable) when assessing the candidate's suitability for a role.

We now have academic conformation that there needs to be a lot of care taken by an interviewer to ensure that they are not mistaking charismatic narcissism in a candidate for confidence and competence.

The study at the University of Nabraska-Lincoln published in Journal of Applied Social Psychology found that narcissists make a better impression in job interviews likely because they are experts at promoting themselves.

As the Huffington Post reported:

‘When the job interviewer challenged the study participants, the non-narcissistic people backed down a little bit. But the narcissistic people actually became even more self-promotional.

The researchers found that the study participants rated the narcissists higher than the non-narcissists, as the narcissists tended to do things like talk a lot and speak quickly, as well as smile at other people.

According to the National Institutes of Health, people with narcissistic personality disorder tend to over-sell their achievements or skills, take advantage of others in order to further themselves, don't respond well to criticism or shame, and often disregard others' feelings.'

Author and Global CEO of Results Coaching Systems, David Rock, articulates the problem as being even potentially greater when you are interviewing people for leadership positions. Generally people who have been in leadership roles previously, and are interviewing for a more senior leadership role, are going to be confident of their ability (although not always) and inexperienced interviewers are always impressed with a candidate's confidence.

The cost of making a poor hiring decision with respect to a leadership role is often vastly greater because the people impacted by the leader's poor leadership skills are subordinates, who are more likely to look for other jobs rather than complain to their boss's boss (or HR) about their nightmare boss.

Recruitment consultants should be trained to conduct effective interviews and be equipped with techniques to test candidates who are charismatic self-promoters, to ensure that there is substance behind the beaming smile, positive body language, rapid answers and laser beam eye-contact.

Here are my top three suggestions:

1. Prepare: Nothing is more important than being fully prepared for an interview which means carefully reviewing the candidate's resume, having your questions ready and noting which areas of the candidate's background needs further explanation or detail.

2. Ask for specifics: As an interviewer your job is to discover facts, not opinions. Asking probing questions such as ‘can you be more specific?, ‘can you give me a recent example of that?' and ‘could you tell me exactly what steps you took to accomplish that?', will help you find out how much substance there is behind a candidate's bravado.

3. Keep cool: A narcissist knows that the best form of defence is attack so if they are feeling under pressure from your questioning they are likely to want to throw the pressure back on you (eg ‘why are you asking me all these questions, don't you trust me?', ‘how much longer will these questions go on', ‘don't you understand what I am saying' etc) in the hope you will get flustered and stop asking them questions that they don't want to answer. Expect this to happen; stay calm and proceed by explaining that these questions are asked of all the candidates.

Confidence in candidates is great but sometimes it's a fine line between confidence and charismatic narcissism. Make sure you are equipped to discover the difference.