From a prospective follow-up cohort study of 56 couples interviewed before marriage, one year post-marriage and eight years post-marriage - published by Thomas B Holman, 1996:
Average age of subjects: 21 - range 18-26.
Time between first acquaintance and engagement: mean 5 months (mode 4 months).
Divorce rate at 8 years c. 4 percent (two couples from the fifty-six).
At eight years post-marriage, couples were asked to evaluate the shortness of the mate-selection process. Most felt it was about right, a few felt it was too long, only one felt it was too short.
Nature of choice: in this group the decision to marry was an individual, a personal choice. Parents, friends and others were sometimes consulted, but often not.
However, couples did seek spiritual input and divine confirmation of their choices: a 'spiritual manifestation' of the rightness of the choice.
Reference: TB Holman. Commitment making: mate selection processes among active Mormon American couples. In Mormon Identities in Transition edited by Douglas Davies. Cassell: London, 1996.
Oh yes... I 'forgot to mention', this study was of active members of the LDS church who were married in a Temple where they were sealed to one another for 'time and eternity'.