Today's Wall Street Journal was very interesting to me, as on November 26th we celebrated our 46th wedding anniversery. 

The Journal article concerned a long study of why some relationships last and some have problems.  In the study, a large percent of the long lasting marriages the key seemed to be that the husband had a close relationship with the wife's family, especially with the wife's father.  If the wife made a good relationship with the husband's family, often the marriage was shorter, due to the husbands family often giving unwanted advice on child raising and family dynamics, since they were close. 

I loved my in-laws as much as I did my own parents, they were great people, very understanding, and later in our marriage I partnered with my FIL in his farming operation, combining it with land we purchased on our own and buying equipment with us paying the difference in trade or my wife and I's share of the partnership.  Were there misunderstandings?  Yes, but my in-laws were great at reaching equal solutions.  It worked for us.

I hope those interested in improving their relationships will read the advice given in this thread, I am not trying to take anything away from the good advice given in it.  I just add this information to provide additional ideas if you can locate today's (Tuesday, November 27) WSJ and read the personal pages of that paper.  It should be available in most librarys, if you don't already subscribe.