The key to a happy marriage finally revealed

Researchers have found that married couples with joint bank accounts fight less over money

Harrison Ford and Calista Flockhart have been happily married for 13 years (Getty Images)

The key to a longer happier marriage is for couples to merge their finances, according to a new study.

Researchers found that married couples who had joint bank accounts fought less over money, felt better at how household finances are managed and have a better relationship.

Couples who pooled their resources tended to feel more that they were ‘in it together’.

The team from Indiana University Kelley School of Business were the first to show a causal relationship to happiness and merged finances though previous studies have shown a link.

Jenny Olson, assistant professor of marketing at Kelley said: “When we surveyed people of varying relationship lengths, those who had merged accounts reported higher levels of communality within their marriage compared to people with separate accounts, or even those who partially merged their finances.

“They frequently told us they felt more like they were ‘in this together.’

“This is the best evidence that we have to date for a question that shapes couples’ futures and the fact that we observe these meaningful shifts over two years, I think it’s a pretty powerful testament to the benefits of merging.

“On average, merging should warrant a conversation with your partner, given the effects that we’re seeing here.”

Their findings, published in the Journal of Consumer Research, came after they recruited 230 couples, who were either engaged or newly married and followed them over two years as they began their married lives together.

They had an average age of 28, three quarters were white and 12 per cent black with 36 per cent having a university education and the average salary was a combined income of $50,000.

Couples had known each other, on average, about five years and had been romantically involved for an average of three years. Ten percent had children.

Everyone began the study with separate accounts and consented to potentially changing their financial arrangements.

This was the first marriage for everyone involved in the study.

Some couples were then randomly assigned to keep their separate bank accounts, and others were told to open a joint bank account instead.

A third group was allowed to make the decision on their own.

Couples who were told to open joint bank accounts reported substantially higher relationship quality two years later than those who maintained separate accounts.

The team think that merging promotes greater financial goal alignment and transparency, and a communal understanding of marriage.

Prof Olson added: “A communal relationship is one where partners respond to each other’s needs because there’s a need, an ‘I want to help you because you need it. I’m not keeping track,.”

“There’s a ‘we’ perspective, which we theorised would be related to a joint bank account.”

Prof Olson said that couples with separate accounts viewed financial decision-making as more of an exchange.

She said: “It’s ‘I help you because you’re going to help me later.

“They’re prepaying for later favors, and that’s tit-for-tat, which we see a bit more with separate accounts.

“It’s ‘I’ve got the Netflix bill and you pay the doctor.’ … They’re not working together like those with joint accounts who have the same pool of money, and that’s more common in business-type relationships.”

Separate accounts also led people to believe it is easier to leave the relationship.

One in five of participating couples did not finish the study, including a significant percentage of those who separated after not merging bank accounts.

They found no gender differences in the results.