
Relationship commitment isn't determined only by how happy someone currently feels.
The investment model proposes that commitment is also influenced by investments—things that would be lost if the relationship ended.
Those investments can include shared friends, memories, time, emotional effort, possessions, routines, or plans for the future.
Greater investments have repeatedly been associated with stronger commitment.
This helps explain why leaving a long relationship can feel much harder than leaving an equally unhappy relationship that started recently.
Sometimes you're not only deciding whether to lose the person—you're deciding whether to lose an entire shared life.
© Journal of Experimental Social Psychology