Joseph:
Chassidishe and Litvishe also tend to daven different nuschaos, have different levush and values of that levush, and follow minhagim and piskei halacha that also differ. So what? The variability in expectations of marriage may well have nothing at all to do with these artificial groupings, and more to do with the role models experienced by these young people prior to marriage. And these role models certainly involve one’s parents and family of origin, but likely others to whom one has been exposed. I am familiar with marital discord among all types of families, and I do not detect mechanisms that distinguish these groupings, nor any meaningful statistics.
I believe that having inadequate preparation for marriage leaves one with unrealistic expectations, and this is unrelated to whether one wears a shtreimel or a bend down hat. It would be curious to hear the assessment of the toanim that represent couples in beis din, who get to hear a good bit about the factors responsible for the problems. Do they second the motion on the hypothesis that the approach to marriage is any different, and does that matter?