27% of participants have kept a financial secret from their partner; and both marital & life satisfaction were lower for participants who have experienced financial infidelity than in those who have not

Jeanfreau, M., Noguchi, K., Mong, M. D., & Stadthagen, H. (2018). Financial Infidelity in Couple Relationships. Journal of Financial Therapy, 9(1) 2. https://doi.org/10.4148/1944-9771.1159

Four hundred and fourteen participants answered questions regarding financial habits within the context of the couple relationship.The Big Five Personality Inventory and a Martial and Life Satisfaction Scale were used to determine the incidence and factors associated with financial infidelity. Results  indicated that 27% of participants have kept a financial secret from their partner. Furthermore, both marital and life satisfaction were lower for participants who have experienced financial infidelity than in those who have not. Finally, conscientiousness, a factor from the Big Five Personality Inventory, showed a significant difference, suggesting that more organized individuals  were less likely to keep financial secrets. Clinical implications are also discussed.