Intrinsic motivation involves how you feel about the actions involved in goal completion themselves. If you resolve to exercise more often, how do you feel about the time you spend exercising? Extrinsic motivation is the value of completing the goal. Exercising more often in order to stay healthy is an extrinsic motivation, because it is about the outcome rather than the joy or pain of the activity itself.
In a 2021 study published in Psychological Reports, researchers explored how intrinsic motivation, the internal drive to act based on interest, personal importance or inner values, affects satisfaction in long-term romantic relationships. Using a sample of 331 adults, including many who were married for over a decade, they found that higher levels of intrinsic motivation were significantly associated with greater emotional closeness, perceived relationship support and marital satisfaction.