Fighting with your partner about money? Blame your parents.

My mother is an heiress. The day that World War II was declared, her family moved from Belgravia in London to one of those stately homes in the English country where the address is just three words: House name, Village name, County name. In her case it was Meredith, Tibberton, Gloucestershire. My family visited it once, and as we approached, one of my brothers and I were remarking on its adorability. My mother interrupted us to note crisply that we were admiring the gardener’s cottage.

The house was hidden down a long hedge-lined driveway. The owners showed us around. The orangery was still there, and the walled garden, and the enormous music room. The bells downstairs had numbers corresponding to upstairs rooms, so the servants knew who had pressed the button signaling readiness for breakfast.

My father, on the other hand, grew up in the Australian countryside. He was born during the Depression; his father was a bank manager. They lived in a house attached to the bank, since farmers don’t really keep bankers’ hours. His formative years were spent watching his dad deal with people struggling to hang on to their farms or to get the bank to lend them enough money to plant crops or feed sheep or hire shearers or care for their children.

His mother died young, and his father remarried. But within a few years, he died too and my father was left to fend for himself and his stepmother. After paying for food, board, transport, and clothes, my dad said that if he saved, he could afford a milkshake once every two weeks. He used to hand-deliver letters near his lodgings so he could keep the tuppence his company provided for stamps.

After a lifetime of rotten luck, dad got a break and was drafted to the Australian Air Force’s marine unit, training to rescue pilots. All of his food, accommodation, clothes, and transport were provided. And when he left the service after six months, he found that his patriotic — or absentminded — employer had continued to pay him.

With the first savings he’d ever had, he traveled to Europe and on his way home, on the good ship SS Orontes, he met my mother, who was on the initial leg of a world tour. Her diary records: “I met a rather vulgar Australian who picks his teeth with his serviette.” My father is no gold digger, but winning her over was possibly the shrewdest financial move he ever made.

Different styles of dealing with money

Unsurprisingly, my dad is incredibly frugal. I’m not talking prudent; I’m talking ascetic. At 85, he still wears at least one shirt he was given for his 21st birthday. Some people have favorite chairs or books; my dad has a favorite piece of rope.

When the heiress married the miser, there were bound to be some interesting transitions. My mother likes fast cars, my father favors cheap ones. My mother loves fine dining and the theater, while my dad prefers to spend his leisure time scraping the extra apple off the peel or gnawing at the heart of a cabbage.

My mother suspected there would always be enough money. My father suspected there would never be. Neither of them was right. They fought about money, but they kept it in perspective. They had separate accounts. My father gave my mother every second paycheck. They agreed upon who would pay for what. And at Christmas and birthdays they gave each other presents that they would have wanted. That’s how one year my dad got a painting, even though he doesn’t really like art, and my mother got a mulcher, even though she doesn’t really like leaf litter.

I didn’t understand what they saw in each other until, somewhat unexpectedly, a postdoctoral student at the Wharton School of Economics explained it. Scott I. Rick advanced the theory — and found some proof— that spendthrifts might be drawn to tightwads to militate against their own tendencies. It turns out that the free-spender/frugal marriage my parents had is quite common. “The more people [are] dissatisfied with their own emotional reactions toward spending, the more likely they [are] to be attracted to a mate with opposing emotional reactions toward spending,” Rick wrote in 2009. It’s possible my parents got together not despite their financial backgrounds, but partly because of them.

(There are two flaws in this theory. One is that my parents don’t concur with it. My mother likes to say that my dad married her for her fortune and her legs, it’s just that the fortune held out a little longer. And the other is that the unions Rick studied often did not last; my parents have been together for 60 years.)

Read more: 12 things successful married couples do with their money

The relationship we all have with money

Everybody comes into marriage with one important relationship they cannot end: the one they have with money. It’s a deep, complicated liaison with a lot of history and often goes unacknowledged. As one of the ancient texts says: where your treasure is, that’s where your heart will be. Money is not just currency. It comes with emotions attached. “There’s a lot of internal feelings related to money because money can also reflect the power and the balance of the relationship,” says Lauren Papp, the director of the Couples Lab at the University of Wisconsin, Madison, and author of several studies on marital conflict. “Money is something that we bring with us from our childhood. So, what does money mean to a person? If someone buys something, is that an act of love, is that an apology, is that just what you expect?” Managing the triangulation of the relationship with a spouse and with moola can be a very tricky business. Sometimes, to paraphrase Princess Diana when her husband, the future king of England, was cheating on her, the marriage can get a bit crowded.

Fights about money, therefore, are not just about having enough and sharing it equally; they strike at the essence of people’s fears and hopes and desires. Fears of being alone and being destitute are intertwined; marriage and wealth both offer a sense of protection and a safe harbor. It’s no accident that people who are under financial pressure get divorced much more often than people who aren’t. It’s also not a coincidence that people often delay getting married until they feel financially secure, which is one of the reasons why there has been a huge drop in marriage rates among those with a high school education or less, and why college graduates get married later, once they have found their footing.

Studies have shown that money is the most commonly reported squabble-starter for couples (followed by kids, although that order is reversed for stepfamilies) and the source of the most heated arguments. And in homes where money is not the most common cause of fights, it’s still the fight that either lasts the longest or in which the same issues just keep coming back without getting resolved.

Finance fights, unlike others, often get more heated over time. In Papp’s study, which got 100 wives and 100 husbands to keep a diary of all the fights they had over a two-week period, with detailed descriptions and ratings for each fight, husbands and wives reported feeling more depressed after money fights than after other fights and husbands reported feeling angrier during those spats than others. Money is also the issue that most couples say is an external problem for them, that is, not one caused within the partnership but by an outside pressure. It’s the number one reason, for example, that many people who live together say they don’t get married.

The rising economic power of women

In the last 37 years, the percentage of wives whose jobs pay them more than their spouses’ jobs do has increased from about 4 percent to almost 25 percent, and a dual income is considered by many to be more of a necessity to cost-neutral family functioning than an anomaly. In 2015, for the first time, according to the Institute for Family Studies, marriages in which the wife was more educated were more common than those in which the husband was. Those are huge shifts that lead to very different negotiations and attitudes to money within couples. Most of us either don’t have a model from our parents on how to handle the issue or don’t like the model we saw.

A generation of women who grew up watching their mothers ask their fathers for money — or struggle to find work and money after a divorce — are now much more likely to be proactive about having their own nest egg. In the course of researching this book I asked more than 200 people how they organized their finances with their spouses. Their answers varied, but it was clear that many of the wives were wary of being dependents.

Men as providers

While on the whole the increased earning power of women has been a total score for men, who, not unlike my dad, increased their income without having to increase their workload merely by marrying the right women, it has had its costs. Studies have suggested that men who earn less than their wives are more prone to infidelity and more prone to use medication for erectile dysfunction. A recent Danish study— from a region of the world known for its progressive views on gender no less — found a 10 percent increase in the use of ED medication among couples in which women earned slightly more than their husbands. It also found that wives who earned more or even equal amounts were more likely to be taking anti-anxiety medication. Research economists at the U.S. Census Bureau reported in 2018 that couples in which wives earned more than husbands tended to minimize the difference when reporting their incomes on census forms. Wives were more likely to understate their income and husbands to overstate theirs.

Why? Researchers suggest that it’s because men are struggling with the idea that they’re not providers. For centuries, the male partner’s job has been to bring home the goods — and it’s probably still the model today’s husbands grew up under — so when they don’t or can’t, they feel like they are failing, specifically as a male. Even in the 21st century, research shows, one of the ways men signal “mate quality,” as they say in zoology, or draw in potential lovers, is to spend money. Splashing around some cash is the human equivalent of fanning out your peacock feathers or sticking out your tortoise neck. So any setback in this area can lead to a loss of confidence in the bedroom, hence the Viagra, or a desire to reassert their alpha-ness, hence the affair, with all its reassurances that they are still attractive and virile. Wives, meanwhile, are walking on eggshells, trying not to provoke their husbands’ feelings of shame but at the same time needing occasionally to bring up money, hence the anti-anxiety meds.

Comparison is the thief of joy, and he’s also a freeloader in marriages. Partners often judge themselves by how they’re doing relative to their spouses. (If you’ve been doing this in secret, relax, there are studies showing it’s completely normal. Yes, especially about income.) The good news is that not all men have been unsteadied by the perception that their wives are doing better than they are on the provider front, especially younger men. An analysis of 21 years of data from Sweden found that women who got promoted doubled their chances of divorce, but only if they were in a marriage with more traditional gender roles. In fact, while a big salary endangered a woman’s marriage in the 70s and 80s, it made little difference to the divorce rate among couples who married in the 90s. And some men really enjoy the glory of their spouses’ successes, either because it’s a testament to their good judgment in women, or because it reflects well on them that they were chosen by somebody who’s such a talent, or, ideally, because they see any win as a win for the team.

One thing to remember during an argument about money

Here’s a key point to remember when hitting play on a recurring fight about your bank account: There’s quite a lot of evidence that marriage enriches people, literally. It’s not just the fact that wealthy people are more likely to get hitched, although that’s true. It’s also not just the fact that there are a lot of rent, insurance, tax, and utilities savings, which is also true. It’s not even that couples who retire as couples are richer than couples who don’t, although that, too, is usually true. There’s a whole other psychological thing at play. For example: happily married men are more responsible, less aggressive, less likely to do something illegal, and more mentally healthy than single ones, so they’re more likely to be earning. This has been documented not just in a bunch of research but chronicled in masterpieces as vaunted as Jane Eyre and Failure to Launch.

Marriage is the ultimate buddy system. When financial troubles hit one of you, there’s another soul with a different set of resources to help you through. And you can nudge each other to make the smart moves.

Excerpted from Marriageology: The Art and Science of Staying Togetherby Belinda Luscombe. Copyright © 2019 by Belinda Luscombe. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.