What primarily determines an individual's commitment to a relationship according to the Investment Model?

The Investment Model emphasizes that the commitment in a relationship is significantly influenced by the investments that individuals have made in it. Investment can refer to various forms of resources, such as time, emotional energy, shared experiences, and mutual goals. As individuals invest more in a relationship, they become more committed to it because they want to protect and justify their investments. This model posits that a higher level of investment leads to increased commitment, which in turn affects the likelihood of staying in the relationship despite potential challenges.

While factors like satisfaction and potential future rewards, personal preferences, compatibility, and external influences like social norms can all play a role in how individuals perceive and engage in relationships, they primarily serve as contextual elements. The core of the Investment Model focuses on how investments create a reasoning for continuing in a relational commitment. Hence, the correct choice revolves around the central idea that what individuals contribute to a relationship significantly shapes their dedication to it.