First, scientists boiled down what makes you fall in love to just 36 questions (although the jury is still out on how well this works) and now economists have come up with a theory that tests whether you truly are in love or not.
According to researchers, just two questions you can work out whether your relationship will last.
Leora Friedberg and Steven Stern from the University of Virginia asked 4,242 couples the two questions, and then asked them again six years later and analysed the data they found.
The two questions are:
1. How happy are you in your marriage relative to how happy you would be if you weren't in the marriage?
2. How do you think your spouse answered that question?
Although the first question may seem a clear indicator of whether you are happy or not, the most important element is whether you can judge your partner's feelings about your relationship, which affects whether couples will be able to stay together and work through problems.
41% of those surveyed could not correctly answer what their partner thought. The researchers explain that this relates to how much effort you will go to to resolve problems, according to the theory of bargaining, and what you will choose to cause conflict about.
The theory continues that couples who are in long-term committed relationships usually have a series of compromises to make, for instance over household chores, or giving up their time for their partner. But if one partner misunderstands the other's happiness, they may bargain too hard on something more trivial, and make their partner more and more unhappy.
Stern gave an example to explain the theory "If I believe my wife is really happy in the marriage, I might push her to do more chores or contribute a larger portion of the family income."
"If, unbeknownst to me, she's actually just lukewarm about the marriage, or she's got a really good-looking guy who is interested in her, she may decide those demands are the last straw, and decide a divorce would be a better option for her."
"In this scenario, pushing a bargain too hard, based on misconception of a partner's happiness, will result in a divorce that wouldn't otherwise have occurred."
Only 7% of the couples surveyed had divorced by the time the researchers revisited the relationships six years later, but the evidence showed that misunderstanding your partner's level of happiness was at the route of most relationship problems. Only 40.9% of the couples accurately identified their partner's feelings.
Freidberg said "This data shows that people aren't being as tough negotiators as they could be, and then we realised that we needed to include caring in the model for it to make sense."
"The idea of love here is that you get some happiness from your spouse simply being happy."
Words: Victoria Gray, Images: Rex Features