Imagine a couple who agreed years ago to be open about money. One of them quietly opens a savings account the other never sees, or lets a credit card balance grow in secret. The other partner keeps every receipt in plain view. On the surface the marriage looks fine, but underneath, the two people are playing by different rules.
A team of marketing researchers set out to understand what happens to couples when partners differ in how likely they are to hide money from each other. Writing in the International Journal of Research in Marketing, they report that this mismatch, rather than the sheer amount of secrecy, tends to be a reliable signal of lower financial and relationship well-being.
A behavior with two people in it
The behavior at the center of the study is what researchers call financial infidelity: engaging in a money-related action you expect your partner would disapprove of, and then deliberately keeping it hidden. Surveys suggest it is fairly common. More than one in five partners admit to it, and among couples who combine their finances, admission rates climb higher.
Earlier work treated financial infidelity as an individual trait, something one person carries. Hristina Nikolova of Northeastern University, along with Jenny G. Olson of Indiana University and Joe J. Gladstone of the University of California San Diego, argue that this misses the point. By definition, the behavior needs two people. So the researchers introduced a different way of looking at it, which they call financial infidelity asymmetry.
The idea is straightforward. Each person in a couple has some baseline tendency toward financial secrecy. Asymmetry is simply the size of the gap between the two partners. In a couple with low asymmetry, both people are similarly transparent. In a couple with high asymmetry, one partner is much more prone to hiding financial information than the other. The researchers note that couples where both partners are highly secretive are rare in practice, so their comparisons mostly pit transparent couples against mismatched ones.
How they measured the gap
The team used several methods and data sources. They started with a pilot study drawing on real bank account information from 622 couples who used a money-management app. During setup, users could choose whether to make each account fully visible to their partner, share only balances, or keep it completely private. The researchers treated the choice to hide accounts as an observable marker of secrecy, then built a score for each partner and measured the gap between them.
Two survey studies followed, involving married couples recruited online. In these dyad studies, 193 couples (Study 1) and 165 couples (Study 2) each completed questionnaires separately and then together. To keep responses honest, both partners had to be physically present and upload photographs of their hands next to their identification at each stage. Each partner filled out a 12-item scale measuring their own tendency toward financial secrecy, and the researchers again calculated the difference between the two scores.
Finally, two experiments (789 and 802 married participants) used hypothetical scenarios. Participants read that they and their spouse had agreed to be open about money, then learned that either both had been honest, only their partner had lied, only they had lied, or both had lied. Because people were randomly assigned to these situations, the experiments let the researchers examine whether the arrangement itself shaped outcomes, rather than the other way around.
What the analyses revealed
Across the studies, a consistent pattern emerged. Couples with a larger gap in financial secrecy tended to hold fewer total assets, reported feeling worse about their finances, and reported lower relationship satisfaction than couples where both partners were transparent. In the pilot study, greater asymmetry was linked to lower balances in real bank accounts.
The researchers also wanted to know whether this gap mattered more than other ways couples can differ. In Study 1, they measured mismatches in personality traits, communication styles, spending tendencies, and the likelihood of other kinds of infidelity. Using a statistical technique that ranks how much each factor contributes to explaining the outcomes, they found that the financial secrecy gap ranked first for all three measures of well-being. It explained roughly 42 percent of the explained variation in total assets, and around 30 percent for both financial well-being and relationship satisfaction, more than any other difference they tested.
The role of shared versus separate goals
Why would a gap in secrecy be linked to worse outcomes? The researchers proposed an explanation and tested it in Study 2. They asked partners whether their financial goals, such as saving, paying off debt, and future spending, felt shared or individual.
The analysis showed that couples with a larger secrecy gap were more likely to report individualized rather than shared financial goals. Having individualized goals was, in turn, linked to lower assets, lower financial well-being, and lower relationship satisfaction. The authors describe this as a chain: when partners differ in transparency, they find it harder to get on the same page, and that lack of alignment is associated with worse results for the couple. When they reversed the order of the variables to test the opposite direction, the connections became weaker or disappeared.
The experiments added another layer. When the researchers combined conditions, couples with a secrecy mismatch reported lower intentions to save toward joint goals and lower relationship satisfaction than couples where both partners behaved the same way. One finding stood out: couples where only one partner lied often looked about as unhappy as couples where both partners lied. In the words of the authors, this suggests “that one partner engaging in financial infidelity may be just as detrimental to well-being as both partners engaging in financial infidelity.”
What to keep in mind
The researchers are careful about what their data can and cannot show. Most of their evidence is correlational, meaning it captures associations rather than proving that a secrecy gap causes worse outcomes. They acknowledge that the reverse is plausible: relationship strain might lead one partner to start hiding money. They argue that the gap is more likely to come first, pointing to prior evidence that secrecy tendencies stay fairly stable over time, while financial goals shift with circumstances. The experiments, where the situation was assigned rather than measured, help address this concern but rely on hypothetical scenarios.
Some other limits are worth noting. The survey samples came from U.S.-based online panels, so the findings may not extend to other cultures or to couples already in counseling. In the experiments, only one member of each imagined couple responded, so the researchers could not capture how both partners felt at once. They also found that total secrecy within a couple predicted lower relationship satisfaction fairly consistently, but its link to actual assets was weaker, which is part of why they emphasize the gap between partners rather than the overall amount.
The authors suggest a few directions for people who work with couples, such as financial planners and therapists. One idea they raise is a “financial date night,” a set-aside time for partners to talk openly about money, ideally with guidance from a neutral third party. Another is reinforcing a sense of shared financial purpose. Whether such steps actually reduce the harms they document is a question the researchers leave for future work.
