People who read books about relationships are usually unhappy about the relationship that they are in. (Exceptions to that rule would be people studying the history of relationships or people interested in relationships for reasons other than self-help.)
Readers of self-help books focused on relationships have usually experienced a lot of pain. They usually either want to repair themselves or improve a relationship that's on the verge of collapse.
Both partners in a relationship in which a lot of conflict is taking place need to understand that there are different sides to people's brains. Most people's brains have a light side and a dark side, a negative side and a positive side, and a frightened side and a courageous side.
People in conflict-relationships also need to understand how to position themselves when they see themselves as being right and their partners as being wrong. Conflicts can't be resolved in situations in which partners aren't open to the possibility that they are wrong or that there is at least an element of truth to their partner’s criticisms.
People who operate from a level of higher consciousness step back in order to examine how their behavior is connected to their psyche when they are in the midst of conflict.
That's a great practice, and meditation is a great tool for helping a person to engage in that type of self-examination. When a person is meditating, they are temporarily removed from the flurry of activity that takes them away from understanding their behavior. If they recognize the connection between their psyche and their behavior, they can move closer toward conducting themselves in an emotionally healthy manner that positively affects their relationship.
Meditation is a mental practice. With practice we learn how to control our reactions to stress and and anxiety triggers. Two important tools to improve our relationships.