Courtship and Marriage Between Hemisity Subtypes

There are four possible hemisity couples:  RM-RF,  LM-LF,  RM-LF,  RF-LM

Which are the most common?  Study of 406 spouses of greater than 5 years duration:

Two thirds of these 203 couples were of Complimentary Hemisity:  RM-LF or RF-LM couples

One third were of the Same Hemisity:  RM-RF or LM-LF couples

Based upon these and other results "Opposites Attract" appears biologically to be the case:  


Within couples, the RMs or RFs are dominant in the home while LMs and LFs are supportive.

Thus RM-RF marriages are less stable than those of RM-LF or RF-LM couples,

 with LM-LF being most stable marriages, but see birth defects in LM-LF offspring.