A lack of reliability in a person can be triggered by a variety of reasons.

Sometimes, it’s just a part of who they are. Some people are simply less organised than others and find it hard to stick to plans or keep arrangements. They may not feel these things are particularly important – they may not even realise that they’re causing annoyance when they are unreliable.

Interestingly, unreliability can stem from uncertainty or a lack of commitment. When we’re feeling unsure of something or the extent to which we feel invested in a relationship, we can sometimes express this in a passive aggressive way – by giving less than we could, or doing so in inconsistent ways. This is a behaviour that can be carried out either consciously or unconsciously – the person who is unreliable in this way might be aware of what they’re doing or it may be something that ‘comes out’ unintentionally.

Unreliability can also come from a desire to have more control over a situation. This applies to both the small stuff and the big. When we make someone wait for us by turning up late, we’re attempting to gain control over their actions. We make them appear to be the person who ‘cares’ more – and so gain the upper hand in a small way. Similarly, when we freeze someone out or refuse to give the emotional support they need, we might make them more dependent on the times we are kind, and so exercise a kind of control over how they feel.

Again, this can be either conscious or unconscious – it may be part of a pattern of planned behaviour designed to undermine the self-esteem of the other partner or it may the expression of a desire that the perpetrator is unaware of. In the case of the latter, this can come from a variety of places, but one of the most common is an inferiority complex – a lack of self-worth that causes them to want to place others on a lower status than themselves.