You might be interested in the textbook that I recommended here, which includes some general information about patterns in relationships that predict how-long-people-that-are-married-stay-married.

I am aware that I am recommending a 500 page textbook in response to your request for advice, and that this is kinda absurd. I am not familiar enough with the material to be able to (given the amount of effort that I am willing to dedicate to the task) summarize the relevant information for you, but figured that the link would be literally better than nothing.