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Genetic Considerations in Human Sex-Mate Selection: Partners Share Human Leukocyte Antigen but not Short-Tandem-Repeat Identity Markers




Previous studies support a role for MHC on mating preference, yet it remains unsettled as to whether mating occurs preferentially between individuals sharing human leukocyte antigen (HLA) determinants or not. Investigating sex-mate preferences in the contemporary Israeli population is of further curiosity being a population with distinct genetic characteristics, where multifaceted cultural considerations influence mate selection.

Method of study

Pairs of male–female sex partners were evaluated in three groups. Two groups represented unmarried (= 1002) or married (= 308) couples and a control group of fictitious male–female couples. HLA and short-tandem-repeat (STR) genetic identification markers were assessed for the frequency of shared antigens and alleles.


Human leukocyte antigen results showed that Class I and/ or Class II single antigen as well as double antigen sharing was more common in sex partners than in control group couples (< 0.001). Married versus unmarried pairs were not distinguishable. In contrast, STR-DNA markers failed to differentiate between sex-mates and controls (P = 0.78).


Sex partnerships shared HLA determinants more frequently than randomly constituted male–female pairs. The observed phenomenon does not reflect a syngenetic background between sex-mates as STR markers were not selectively shared. Thus, sex-mate selection in man may contravene the evolutionary pressure for genetic diversity in regard to HLA.