In romantic relationships, "doormat" behavior can lead a partner to stop taking the person's feelings seriously, as the lack of boundaries erodes trust and integrity.

Constantly forgiving unfair treatment can erode a person's self-respect and clarity about their own self-concept.

Calling someone a "doormat" is an informal criticism used to describe a person who allows others to treat them poorly without defending themselves. It often refers to someone who is perceived as "too nice," putting others' needs before their own to a self-detrimental degree. The Psychology of Being a "Doormat"