While community pressure may be a significant factor, They "stay married" because that is how a mormon is defined. If you divorce, you're out. Saying Mormons have a high rate of staying married is like saying farmers have a high rate of agriculture. There are plenty of divorced ex-mormons who are not included in the statistics.
cookcounty,
thanks for your addition to the discussion.
I know they also have the bizarre belief that the souls of unborn humans are lined up in heaven, waiting to be born - which is why they insist on large families - to rescue them and give them bodies.
The more you learn about their beliefs, the more you realize mormonism is not a Christian belief, but a polytheistic religion of many gods and non-Biblical ideas, stitched together. Quite different than what you see portrayed in their ads.
I’ve nothing against individual mormons. I several friends who were raised that way and just accept it all. It is mormonism itself that is the weird thing.