Research found that when one partner has an affair in a relationship, the betrayed partner almost always?

The correct choice reflects a significant emotional impact experienced by the betrayed partner after an affair. Research in the area of infidelity indicates that such a betrayal can lead to symptoms akin to post-traumatic stress disorder (PTSD). This includes experiencing intrusive negative thoughts, hypervigilance, emotional distress, and a heightened sense of anxiety or fear.

The betrayal shakes the foundational trust within the relationship, causing the betrayed partner to relive the feelings of abandonment or betrayal. This trauma can manifest in various psychological symptoms, contributing to a chaotic emotional state, similar to what individuals might experience after a traumatic event.

In contrast, the other options do not accurately capture the typical response of a betrayed partner. For instance, developing increased fondness and admiration is unlikely as the emotional fallout usually involves hurt and anger rather than positive feelings. Rejecting the reality of the affair often occurs in the short term as a coping mechanism, but it is not a prevalent long-term response. Lastly, attempting to contact the affair partner's lover is not a common reaction, as many betrayed partners are more focused on processing their own feelings rather than engaging with the other individual involved. Thus, experiencing PTSD symptoms and intrusive negative thoughts effectively represents the turmoil faced by the betrayed partner in the context