By Matthew Warren

As humans we all have psychological needs that we are driven to fulfil, be they companionship or safety, a sense of belonging or personal growth. And we often meet these needs through our relationships with others: they care for us, make us feel secure, and help us develop as individuals.

When we are in romantic relationships, our partners are commonly the main source for fulfilling those needs. But sometimes they are away, or are simply not equipped to meet our particular needs. In those cases we turn elsewhere, to friends, family and others in our lives. This may benefit us personally — but how does it affect our relationship?

To find out, Laura Machia and Morgan Proulx at Syracuse University conducted a series of studies, published in Personality and Social Psychology Bulletin, looking at need fulfilment amongst American adults in relationships. The first study drew on data collected in the mid-1990s from almost 4,700 participants of the Midlife in the United States longitudinal study. Participants reported how many hours per month their partner, and others outside of their relationship, fulfilled one particular need — emotional support. They also completed a number of scales measuring the quality of their relationship and how often they’d thought that their relationship could be in trouble.

The researchers found that the more emotional support people received from outside their relationship, the more negatively they rated their relationship and the less stable they felt it was. And it wasn’t simply that these participants were making up for a lack of fulfilment from within the relationship: the findings held even when the researchers took into account the extent of support provided by participants’ partners.

Instead, the team wondered whether having one’s needs met outside of a relationship made people more aware that there were other viable options to turn to than just a partner. In a subsequent study, they gave 413 university students questionnaires measuring the “perceived quality of alternatives”, rating their agreement with statements like “My needs for intimacy, companionship, etc., could easily be fulfilled in an alternative relationship.” Participants also completed scales measuring how often their partner, and other people, met their needs (for instance, self-improvement or companionship), as well as how often they thought about ending their relationship.

The team found that the more participants’ needs were fulfilled within a relationship, the worse they perceived the option of going to other people to meet their needs. But the more they actually received fulfilment from those outside sources, the better they rated them — and the more they thought about ending their relationship.

It’s an intuitive finding: when people go outside of their relationship to try and meet their needs, they learn there are other options out there and they don’t have to rely just on their partner. And that doesn’t necessarily mean they are finding other romantic partners, the authors add. Rather, receiving fulfilment from outside their romantic relationship “allows an individual to feel that being single, spending time with friends, or finding a new romantic partner at some point is a more viable option for them, in that their need fulfilment would not suffer considerably, should they opt to take one of those paths.”

For the most part the study didn’t distinguish between different kinds of psychological need, so it remains to be seen whether there are particular needs to which the results apply most strongly — perhaps those that are closely linked to romantic relationships, for instance, like security and intimacy. There may also be individual differences in how susceptible people are to the effects, something the authors say they will look at in future work.