Relationships: what type do you want?
Long-term pairing prevalent but environmental cues can factor, study finds
Do you prefer vanilla or chocolate icecream? Chances are you do prefer one, but liking one doesn’t necessarily rule the other out. Even die-hard vanilla fans might be tempted by a new brand of chocolate in the right circumstances. Could relationship preference be the same?
While men and women typically seek long-term partners, the prevalence of one night stands, affairs and “friends with benefits” arrangements suggest that humans also have a taste for casual sex.
Evolutionary psychologists believe that human relationships tend to fall into one of two camps — long-term committed mating or shortterm casual mating. Both would have led to reproduction among our ancestors, but which provided the best outcome would have been dictated by societal and environmental circumstances, for example, the availability of resources.
In times of plenty, ancestral men and women would have been able to mate casually with fewer consequences than normal. Men who mated with women and then left had a fair chance that any resulting offspring would survive with little to no investment on their part. Women, in turn, could mate with a highly attractive man who was unlikely to stick around, knowing that any resulting offspring would be likely to both survive and possess the high quality genes of their father.
Change the environment to resource poor, and the consequences of short-term mating also change. It becomes harder for young to survive and thrive with just the investment of their mother and her family. Under these conditions, seeking long-term committed partners would have been more beneficial.
Due to the varying benefits of short and long-term relationships, humans have evolved to be “mixed strategy” maters, retaining a preference for, and capacity to engage in, both long and short-term options.
We believe that humans have evolved a psychological “organ” which tracks changes in the environment and calibrates relationship preferences accordingly.
To test this idea, we recorded 414 volunteers’ relationship preferences by showing them a number of opposite sex suitors, and asked them to decide if they would prefer a longterm or short-term relationship with each. Then we exposed them to different stimuli designed to signal changes in the environment, and asked them to revisit their decisions.
For example, to signal resource abundance, we exposed participants to images of luxury items including jewellery, fast cars and mansions. We also signalled the need to care for young children and the presence of dangerous animals in a similar way.
In every experiment, we found changes in relationship preferences in line with evolutionary predictions. Most notably, we found that, relative to a control group, participants shown cues that the environment was resource-rich tended to show an increased preference for short-term mating. Importantly, preferences for long-term mating didn’t change.
The results suggest that people have separate degrees of preference for both short-term and long-term relationships, and which one is ultimately pursued depends on the relative strengths of that preference.
So if a person finds themselves in a committed relationship, it could be because their preference for longterm mating overshadows their preference for casual mating. But a preference for the latter may still be there, lurking in the background.
Does this mean the end of relationships as we know it? Unlikely. However, if someone were to be exposed to strong and persistent signals that their environment had changed in some way — following a job promotion, or during an economic recession, for example — then this might cause them to change the type of relationship they want.