As ‘selfies’ stream in on our phones, the words ‘narcissistic’ and ‘narcissism’ are in the air, and evidence does suggest that, as a society, we’re becoming more boastful and self-absorbed. Is that narcissism? Yes, but you have probably only met a handful of people who have a ‘narcissistic personality disorder’ (NPD). They are the extreme. We all can behave narcissistically at times or in some relationships. NPDs follow the pattern consistently, with everyone, and do a great deal of damage.

The most recognised definition of someone with NPD (from the manual psychologists use for diagnosis) once described brash show-offs like Boyer’s boss; it has since been rejigged. The new one, DSM-5, also includes people who are insecure, with low or widely fluctuating self-esteem. Their goals and standards are unrealistic, because they either seek a superhuman status or else feel entitled to praise for sitting up in a chair. They’re callous or uninterested, which keeps their relationships superficial. They value you only because you admire them or serve another purpose.

The clues tend to be obvious, so why do we disregard them? Because narcissists sometimes appeal to our own narcissism, perhaps. As clinical psychologist Ellen Walker points out: ‘They’ll say things like, “Oh, it’s so great to finally meet someone in this town who knows what fine dining is or can carry on an intelligent conversation.” This makes you feel good.’ Of course, once they think you sound dumb in any way, the romance is over. In my experience, boasts about being kind and warm mean the opposite. Public rudeness is another giveaway. But I wouldn’t worry that you have an NPD, if only because you read this article through to the end.

DEALING WITH NARCISSISTS…

…at the office. NPDs take credit for a group’s work and pass on blame, says University of Georgia psychology professor Keith Campbell, the co-author of The Handbook Of  Narcissism And Narcissistic Personality Disorder (John Wiley & Sons, £110). A narcissistic boss can be hell. ‘Try to get away,’ he says, but if you can’t or you decide that the job is worth it, Campbell offers this advice: ‘Keep your head low. Use the organisation’s rules to protect yourself. Keep good records. You might use flattery or let them take credit for your work – that’s Plan C.’ Your good performance could be threatening, but other people usually can see what’s going on. Build allies without badmouthing.

Be prepared to be fired unexpectedly. ‘They’re seeing reality through a filter, so you don’t know what they see, and it could be “Boom, you’re out.” Anything that makes them look bad or disappoints them could make them angry,’ Campbell says. Don’t talk about having a headache or a fight with your boyfriend. And ‘don’t ever cry in front of a narcissistic boss, or your job will be in great jeopardy,’ adds Walker. They’re callous, remember. Establish boundaries and stick to them.

…in the family. Boundaries are also necessary when you’re stuck with a narcissist in your personal life. Don’t confide. With a close relative like a mother or sister, Campbell suggests creating ‘structure’; for example, you might insist on talking only once a week, at a pre-set time because you want to give her your ‘full attention’. ‘Take her in small doses,’ he says. ‘Keep the relationship in the narrow, most rewarding band.’

If you stick to your own rules, ‘you won’t be the favourite, but secretly, they will respect you,’ Walker says. Don’t expect sympathy in times of trouble, either. ‘It might be a source of humiliation to your mother to realise that her offspring is not perfect,’ Walker says.

…within a marriage. Why would you want to stay? But if you do or must, then narcissistic partners will be at their best ‘if you let them have a lot of freedom and control over their own life,’ says Campbell. ‘They might have affairs and drop you if you’re not meeting their ego needs.’ You may feel very lonely. NPDs tend to act ‘as if they are always right and their partner is wrong or incompetent,’ says Lisa Firestone, director of research and education at the Glendon Association, in Santa Barbara, California. Campbell says therapy can work: ‘They can change if they want to – the problem is they usually don’t want to. Use leverage or pressure – say, “you’ll lose your family” for example.’ And if comes to it, he adds: ‘In a divorce, get a really good lawyer.’