Relationship quality tends to gradually decline well before infidelity happens, study finds

A 12-year study in Germany reported that infidelity in a romantic relationship is preceded (but not followed) by a period during which the well-being of partners in the relationship and the functioning of the relationship is gradually decreasing. This was observed in both perpetrators and victims of infidelity. The study was published in Psychological Science.

Sexual infidelity, also known as cheating or unfaithfulness, is one of the often reported reasons for the separation of couples. It is a relationship transgression that most societies condemn very harshly. When relationships are studied, infidelity is found to be associated with a range of problems in relationship and individual functioning. However, it is unclear whether infidelity leads to relationship troubles or it happens as a consequence of trouble in the relationships.

Psychological theories of intimate relationships see infidelity as an important cause of distress in a relationship. This is why couple counseling approaches to infidelity mainly focus on managing the painful emotions that are present after infidelity has occurred. On the other hand, researchers more recently proposed that infidelity might actually be a consequence of a relationship that does not function well, rather than the cause.

Study author Olga Stavrova and her colleagues wanted to examine whether infidelity is a cause or a consequence of poor relationship functioning by reasoning that if it is a cause of poor relationship functioning, this decrease in the functioning of the relationship would happen after infidelity occurred. However, if it is a consequence of poor relationship functioning, that poor functioning will be present before infidelity happens.

They reviewed data from the Panel Analysis of Intimate Relationships and Family Dynamics, a study that followed more than 12,000 people in Germany since 2008 and collected records on relationships and well-being of participants and their children. The study authors selected two groups from this pool of participants – the infidelity sample and the control sample.

The researchers distinguished between three types of infidelity: those who committed infidelity (perpetrator infidelity), those who reported their partner had committed infidelity (victim infidelity), and participants reporting that both they and their partner committed infidelity (mutual infidelity). However, they excluded the last group (mutual infidelity) from their analysis as there were not enough participants in it.

The control sample consisted of individuals in a committed relationship who did not report infidelity in their relationship and who were matched with the infidelity sample on a range of demographic factors.

The researchers analyzed data on infidelity, life satisfaction, relationship commitment, and relationship and personal well-being. Both individuals who committed infidelity and their partners reported lower life satisfaction and relationship satisfaction, as well as higher relationship conflict.

After the time of infidelity, perpetrators reported lower self-esteem, lower relationship satisfaction and intimacy, and more relationship conflicts. These changes were less clear for victims of infidelity. “They reported less self-esteem and more relationship conflict after (vs. before) they were cheated on but experienced no change in other indicators of well-being. We found no evidence for partner effects, with the exception of lower relationship satisfaction reported by cheaters’ partners.”

The researchers observed a gradual deterioration of most indicators of relationship well-being in both victims and perpetrators of cheating. This gradual deterioration started before cheating happened.

When commitment to the relationship was taken into account, results showed that individuals with a high level of commitment to the relationship experienced no change or deterioration in well-being after cheating on the partner. The same was observed in victims of infidelity. However, in people with lower levels of commitment to the relationship, well-being improved after cheating.

Results also showed that men were more likely than women to engage in infidelity. Finally, participants who separated from their partner after infidelity, but did not find a new partner afterwards, experienced a deterioration in life satisfaction after infidelity. This was not the case with individuals who found a new partner or stayed together with their partner following infidelity.

Additionally, the decline in well-being that preceded infidelity did not recover in the following years. The exceptions were people with lower initial commitments and unfaithful women.

The study sheds light on an important aspect of romantic relationships. However, it should be noted that this study was based on data that were already collected and authors had no influence on what data were collected. Additionally, the question asking about infidelity was not sufficiently clear (what exactly constitutes an “extra-marital affair” – does flirting count?) and it did not take into account the possibility of consensual non-monogamous relationships.

The study, “Estranged and Unhappy? Examining the Dynamics of Personal and Relationship Well-Being Surrounding Infidelity”, was authored by Olga Stavrova, Tila Pronk, and Jaap Denissen.

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