Keck Private Investigations

Suspecting a spouse of infidelity is a difficult situation for anyone. While every relationship is different, research and real-world casework reveal several behavioral patterns commonly associated with unfaithfulness. Understanding these signs can help individuals approach the situation with caution and clarity.

Infidelity is more common than many people realize. According to the General Social Survey, about 20 percent of married individuals in the United States report having cheated on their spouse at least once (Wang, 2020). The American Association for Marriage and Family Therapy found similar results, with 15 percent of married women and 25 percent of married men reporting at least one extramarital affair (AAMFT, 2023).

Researchers have identified certain behavioral changes that may indicate infidelity. One major sign is a sudden increase in secrecy or privacy. This can include hiding a phone, changing passwords, or deleting messages (Buss, 2017). A noticeable shift in daily routines, such as coming home later than usual or being less available, is another commonly reported sign (Allen et al., 2005). Unexplained changes in intimacy, both physical and emotional, are also frequently cited in the literature (Mark et al., 2011).

Another pattern involves unexplained expenses or changes in spending habits. Studies report that financial infidelity often occurs alongside emotional or physical affairs (Olmstead et al., 2016). Receipts for gifts, unexplained withdrawals, or new credit card statements may point to activities outside the marriage.

Increased defensiveness or hostility when questioned about schedules or activities can also raise concerns. Experts note that people engaged in infidelity may project guilt or anxiety as anger or irritability (Glass & Wright, 1992). Conversely, some individuals may suddenly become more attentive or affectionate, attempting to offset guilt or suspicion.

It is important to recognize that these signs do not prove infidelity. Many of these behaviors have innocent explanations. However, when several changes appear together and persist over time, they may warrant closer attention. Consulting a professional investigator can provide clarity, documentation, and peace of mind.

Infidelity has significant consequences for spouses and families. Research shows that discovering a partner’s infidelity often leads to symptoms similar to post-traumatic stress, including anxiety, intrusive thoughts, sleep problems, and depression (Gordon et al., 2004). Trust, which is central to any relationship, is deeply damaged and can take years to rebuild, if at all. Many spouses report a decline in self-esteem and self-worth after learning of an affair (Cano & O’Leary, 2000).

The impact extends to children and the wider family. Studies have found that children exposed to parental infidelity may experience confusion, anger, and insecurity, especially if the infidelity leads to separation or divorce (Amato & Previti, 2003). Family routines and communication often suffer, creating long-term effects on the family’s emotional health.

At Keck Private Investigations, we approach each case with professionalism, confidentiality, and respect for all parties involved. Our goal is to provide clear answers based on facts, not assumptions.

References

Allen, E.S., Atkins, D.C., Baucom, D.H., Snyder, D.K., Gordon, K.C., & Glass, S.P. (2005) ‘Intrapersonal, interpersonal, and contextual factors in engaging in and responding to extramarital involvement’, Clinical Psychology: Science and Practice, 12(2), pp. 101–130.

Amato, P.R. & Previti, D. (2003) ‘People’s reasons for divorcing: Gender, social class, the life course, and adjustment’, Journal of Family Issues, 24(5), pp. 602–626.

American Association for Marriage and Family Therapy (2023) ‘Infidelity’. Available at: https://www.aamft.org/Consumer_Updates/Infidelity.aspx

Buss, D.M. (2017) The Evolution of Desire: Strategies of Human Mating, Basic Books.

Cano, A. & O’Leary, K.D. (2000) ‘Infidelity and separations precipitate major depressive episodes and symptoms of nonspecific depression and anxiety’, Journal of Consulting and Clinical Psychology, 68(5), pp. 774–781.

Glass, S.P. & Wright, T.L. (1992) ‘Justifications for extramarital relationships: The association between attitudes, behaviors, and gender’, Journal of Sex Research, 29(3), pp. 361–387.

Gordon, K.C., Baucom, D.H., & Snyder, D.K. (2004) ‘An integrative intervention for promoting recovery from extramarital affairs’, Journal of Marital and Family Therapy, 30(2), pp. 213–231.

Mark, K.P., Janssen, E., & Milhausen, R.R. (2011) ‘Infidelity in heterosexual couples: Demographic, interpersonal, and personality-related predictors of extradyadic sex’, Archives of Sexual Behavior, 40, pp. 971–982.

Olmstead, S.B., Pasley, K., & Fincham, F.D. (2016) ‘Insights into financial infidelity’, Journal of Financial Therapy, 7(1), pp. 41–62.

Wang, W. (2020) ‘Who Cheats More? The Demographics of Cheating in America’, Institute for Family Studies. Available at: https://ifstudies.org/blog/who-cheats-more-the-demographics-of-cheating-in-america