Overview of Infidelity Research - Does Personality Determine Fate
Infidelity is one of the most common causes of relationship dissolution, and while its prevalence varies by survey methodology and definition, the proportion of people who experience infidelity at least once in their lifetime is estimated at 20-40%. This high prevalence indicates that infidelity is not simply a problem of "bad people" but a risk that many can face.
Personality traits have been studied as predictors of infidelity, but an important caveat is necessary here. Personality is a "risk factor" for infidelity, not a "determinant." Possessing certain personality traits statistically increases the probability of infidelity, but it does not mean that everyone with those traits will inevitably be unfaithful. Environmental factors, relationship quality, availability of opportunity, and personal values all interact in complex ways.
With this premise in mind, let us examine which personality traits are associated with infidelity risk based on empirical research. The goal is not to "identify people who will cheat" but to understand risk factors in order to facilitate preventive relationship building.
Low Conscientiousness - Lack of Impulse Control and Long-Term Perspective
Among the Big Five traits, low Conscientiousness is the most consistently associated with infidelity. Meta-analyses report a significant negative correlation between conscientiousness and infidelity. People low in conscientiousness tend to have weak impulse control and prioritize immediate desires over long-term consequences.
Multiple mechanisms link conscientiousness to infidelity risk. First is weak impulse control. Most infidelity is not planned but occurs when an opportunity arises and the impulse cannot be suppressed. People high in conscientiousness excel at controlling impulses even when facing temptation, considering the long-term impact on their relationship.
Second is the ability to maintain commitment. Conscientiousness is associated with sustained effort toward goals, which also affects the ability to maintain relationship commitment over time. People low in conscientiousness, when the relationship enters a difficult period, tend more strongly toward escaping into a new relationship rather than making the effort to resolve problems.
Third is the strength of normative awareness. People high in conscientiousness tend to value social norms and promises, making it easier for them to internalize the norm of "loyalty to one's partner." People low in conscientiousness have lower conformity to norms and tend to have a lower psychological barrier to "breaking rules."
Low Agreeableness - Lack of Empathy and Consideration for Partners
Low Agreeableness is also a significant predictor of infidelity risk. People low in agreeableness have weaker empathy for others' emotions and tend to prioritize their own desires over others' feelings. The reduced ability to imagine how much a partner would be hurt by infidelity weakens behavioral inhibition.
Low agreeableness also affects how dissatisfaction is expressed within relationships. People high in agreeableness tend to communicate dissatisfaction constructively and attempt problem-solving, while people low in agreeableness tend to either express dissatisfaction directly or seek to fulfill their needs outside the relationship. The latter pattern is more likely to lead to infidelity.
Additionally, low agreeableness is associated with "manipulativeness." People low in agreeableness have less resistance to using others for their own purposes and tend to disregard the feelings of affair partners as well. This overlaps with the Dark Triad domain (Machiavellianism, narcissism, psychopathy).
Neuroticism and Infidelity - The Role of Anxiety and Need for Validation
The relationship between Neuroticism and infidelity is not as linear as with other traits, but a significant positive correlation has been reported. The mechanisms by which highly neurotic people arrive at infidelity are qualitatively different from those involving low conscientiousness or agreeableness.
The first mechanism is the need for validation based on relationship anxiety. People high in neuroticism have unstable self-evaluation and sometimes cannot confirm their self-worth through their partner's approval alone. Sexual or romantic interest from others outside the relationship can temporarily function as a means of confirming self-worth. Related books can also be found at related books (Amazon).
The second mechanism is infidelity as a coping strategy for negative emotions. People high in neuroticism frequently experience negative emotions such as anxiety, depression, and anger, and may resort to stimulating behaviors as a coping mechanism. The excitement and novelty that infidelity provides functions as temporary escape from negative emotions.
The third mechanism is an indirect pathway mediated by low relationship satisfaction. People high in neuroticism tend to experience more conflict within relationships and are prone to declining relationship satisfaction. Declining relationship satisfaction is one of the most powerful proximal factors for infidelity, and neuroticism indirectly increases infidelity risk through relationship satisfaction.
Extraversion and Openness - The Influence of Opportunity and Curiosity
Research results regarding the relationship between Extraversion and infidelity are mixed. People high in extraversion are sociable, have more contact opportunities with the opposite sex, and tend to have higher sexual interest. These factors increase the "opportunity" for infidelity, but extraversion itself does not motivate infidelity.
Within extraversion, the "sensation-seeking" facet is particularly associated with infidelity risk. People with a strong tendency to seek new experiences and excitement are more likely to feel bored with the stability of long-term relationships and to develop heightened desire for new romantic or sexual experiences. On the other hand, the "warmth" and "gregariousness" facets of extraversion do not necessarily increase infidelity risk.
Regarding Openness to Experience, the sexual openness facet has been reported to be associated with infidelity. People with high curiosity about sexual diversity and novelty tend to find it difficult to be satisfied with exclusive one-on-one relationships. However, people high in openness also tend to choose non-traditional relationship forms (such as open relationships), and consensual non-exclusive relationships should not be equated with "infidelity."
Factors Beyond Personality - Relationship Quality, Opportunity, and Situation
Personality traits explain part of infidelity risk but are by no means the complete picture. The most powerful predictors of infidelity are actually not personality but "low relationship satisfaction" and "the existence of opportunity." No matter how high someone's conscientiousness, if they are in a seriously dissatisfying relationship and an attractive alternative partner exists, infidelity risk increases.
Relationship quality factors include low sexual satisfaction, lack of emotional intimacy, neglect or dismissal from a partner, and communication breakdown. These factors increase infidelity risk independently of personality, and the simple formula "good personality means no infidelity" does not hold.
Opportunity factors include close contact with the opposite sex at work, physical distance due to business trips or living apart, and the proliferation of social media and dating apps. Technological advancement has dramatically increased opportunities for infidelity, and even people with low personality risk face temptation more frequently in opportunity-rich environments.
Furthermore, situational factors such as the influence of alcohol, accumulated stress, and life transitions (midlife crisis, parenting stress, etc.) are also important. These factors temporarily weaken impulse control and function as "triggers" that release behaviors that would normally be suppressed.
A Preventive Approach - Using Risk Factor Understanding for Relationship Building
The purpose of understanding infidelity risk factors is not to suspect one's partner but to preventively strengthen the relationship. It is important to recognize personality risk factors in yourself or your partner and then intentionally construct an environment and relationship quality that mitigates those risks.
If there is a tendency toward low conscientiousness, external structures and routines can supplement impulse control. Regular check-ins with your partner, clear agreements about relationship boundaries, and strategies to proactively avoid tempting situations are all effective.
If neuroticism is high, it is important to have sources of self-worth outside the relationship. Building a foundation of self-esteem that does not depend on partner approval - through hobbies, friendships, career - can reduce the motivation to seek validation outside the relationship.
Most importantly, continuous effort to maintain and improve relationship quality is essential. Regularly checking sexual satisfaction, emotional intimacy, and communication quality, and addressing problems while they are still small, is the most effective prevention against infidelity. Personality is difficult to change, but relationship quality can be improved through intentional effort.