There is a conundrum at the heart of understanding how judgements work in relationships. On the one hand, we need to accurately assess whether someone is right for us because it is such an important decision – this is someone who we might potentially spend the rest of our lives with. On the other, a lot of evidence suggests that we are very bad at evaluating the qualities of the people closest to us.
Love blinds us to the realities of the people around us. In one study, participants in relationships were asked to write about recent romantic moments, or random events, that they had shared with their partner after being shown a photo of an attractive stranger. While writing down their story, they ticked a box every time their thoughts drifted back to the photo of the stranger. The participants who wrote about romantic anecdotes ticked the box one-sixth as often as the group who wrote about random events. It seems that we are much less likely to be distracted by attractive alternatives while concentrating on the things we love about our partner.
Across most cultures, there is good evidence that humans prioritise attractiveness, kindness and status (or, the access someone has to resources) when looking for a new partner. These qualities are referred to as the "Big Three". How we prefer these qualities to manifest varies across cultures, as most cultures have different standards of beauty, for example. Or when it comes to status, some people might value a particular job or level of income, while for other people a rank or social class is more important. But we can generalise to say that all humans are interested in physical attraction, how nice a person is, and whether they can provide for you. You would think, therefore, that we should be quite good at measuring these qualities – otherwise the behaviour would not have evolved in humans.
If you judge the attractiveness of someone as greater than their objective level of attractiveness (or greater, say, than a random person would rate them) you are said to have positive directional bias – in other words, it is as if you are wearing rose-tinted glasses. The same applies the other way if you are overly critical of someone’s level of attractiveness – and is called a negative directional bias. It is normal for people in relationships to rate their partner’s attractiveness, kindness and status as higher than others might.
Directional bias – consistently ranking our partner’s qualities higher than other people would – is one of the most important factors that determines how happy you are in your relationship. If you ask people what they want from a relationship, they might say that they want to be seen authentically in a way that matches their self-perceptions. But people also quite like their partner to see them as a bit better than they really are. So, when we are secure in our relationships, this manifests as being overly positive.
When your friends are in seemingly unsuitable relationships, remember that they are probably seeing their partner as better than they are, and they might be impervious to your advice and unable to see better options elsewhere. Their assessment may well be wrong, but we are all guilty of it.