Trust fools you into remembering that your partner was more considerate and less hurtful than they actually were, say psychologists who examined the role of trust in biasing memories of transgressions in romantic partnerships. 

People who are highly trusting tended to remember transgressions in a way that benefits the relationship, remembering partner transgressions as less severe than they originally reported them to be. People low on trust demonstrated the opposite pattern, remembering partner transgressions as being more severe than how they originally reported them to be, they concluded. 

"You can remember your partner as better or as worse than he/she really was, and those biased memories are important determinants of how you think about your partner and your relationship," said lead author Laura B. Luchies of  Redeemer University Collegein Ontario.

We all know that trust is crucial to a well-functioning relationship.

"One of the ways that trust is so good for relationships is that it makes us partly delusional," said Eli J. Finkel, co-author of the study and professor of psychology at Northwestern. The current psychological reality of your relationship isn't what actually happened in the past, but rather the frequently distorted memory of what actually happened. 

"This research presents a newer, deeper understanding," Finkel said. "It reveals that trust yields relationship-promoting distortions of the past."

Said Luchies, "If you talk to people who really trust their partner now, they forget some of the negative things their partner did in the past. If they don't trust their partner much, they remember their partner doing negative things that the partner never actually did. They tend to misremember."