Psychologists talk about 'personality types' when they are describing ways of thinking and behaving that are common to us all, such as being a bit selfish/self-focused, obsessive about tidiness, or consistently avoiding things we feel uncomfortable with. We are all on a spectrum with these traits, but for some of us they are much more pronounced than others.
You may also have heard the term 'personality disorder', which is when someone strongly exhibits characteristics of one or more of these types, to such an extent that it affects their whole personality (not just their mood, as in a 'mood disorder' like depression) and typically makes life very difficult for themselves and the people around them.
Another term commonly used (and often misused) in the media is 'narcissistic'. Correctly used, narcissism describes someone who tends to be extremely self-focused, viewing the world and the people they encounter as being there to serve their needs. They will probably have an Entitlement schema and so feel entitled to special treatment, attention and recognition of their unique skills, knowledge or personal qualities. Narcissistic people also have a black-and-white view of the world and how things should be, with a strong belief that they are always right and that bad things in their life are other people's fault, not theirs.
Again, it's important to remember that we all have some of these traits and beliefs – it's how strongly those beliefs are held that's key. When these beliefs are deeply and rigidly held, then someone might be diagnosed with narcissistic personality disorder (NPD). Because people with NPD tend to be extremely single-minded about getting what they want, we see these individuals at the top of a number of professions, such as banking, politics, law, professional sports, music and acting.
It's tough to be in a relationship with a narcissistic person, because they tend to be very perfectionistic and critical. Because empathy is not their strong suit, they just don't get why or how they have hurt someone, and will tend to fly into a rage when challenged or criticised (behaving like the angry little person above). If any of this sounds like someone close to you, they may need help in learning to relate to others in a more compassionate, less self-serving way.
Schema therapy can help with that, if they can be persuaded to come along, which is often challenging. People with these characteristics usually end up in therapy because people – an angry boss or partner on the verge of leaving – have pressurised them to do so.
The most important thing is to understand why they are acting in baffling and sometimes hurtful ways – and remember that it's definitely not your fault. Knowledge is power, so read up on narcissism (I strongly recommend Disarming the Narcissist: Surviving and Thriving with the Self-absorbed, by Wendy Behary, a leading schema therapist specialising in narcissism) and develop strategies for protecting yourself and maintaining healthy boundaries.
If you or someone close to you is narcissistic, and you would like help with that, email firstname.lastname@example.org