It turns out your choices in the supermarket may be more important than you think.
Brands may have more of a stakehold in our life than we realise.
Recent research has suggested that preferring different brands may be more important than personality traits or even shared interests.
Gavin Fitzsimmons, a marketing professor at Duke University's Fuqua School of Business said of the study, published in the Journal of Consumer Research:
People think compatibility in relationships comes from having similar backgrounds, religion or education.
But we find those things don't explain how happy you are in life nearly as much as this notion of brand compatibility.
The researchers found that partners who had low power in their relationships (who couldn't shape their partner's behaviour) usually submit to the others' preferred brands.
Former Fuqua PhD student Danielle Brick, now of the University of New Hampshire, said:
If you are lower in relationship power and have different brand preferences than your partner, you're probably going to find yourself stuck with your partner's favourite brands, over and over again.
This could lead to a death-by-a-thousand-cuts feeling.
Most couples won't break up over brand incompatibility, but it leads to the low power partner becoming less and less happy.
The researchers used brand preferences in soda, coffee, beer, chocolate, and cars to study individuals and couples over the course of two years.
They found the results aligned with findings about relationship power and happiness, and although not seen as important conventinally, could weigh down a relationship. Brick said:
If you like Coke and your partner likes Pepsi, you're probably not going to break up over it -- but 11 years into a relationship, when he or she keeps coming home with Pepsi, day in and day out, it might start to cause a little conflict.
And if you're the low-power person in the relationship, who continually loses out on brands and is stuck with your partner's preferences, you are going to be less happy.