Some hives just have nasty tempers.  When I was working the main bee yard
at Cal Poly, back in the mid '70's, we always joked about "Damn, no foulbrood
in the #4 hive this time, either."  That was because there was a noticable
difference in hive #4 from all the rest of the hives in the bee yard.  These
gals were nasty customers, and we really would have relished a chance to just
get rid of them, altogether.  (It was eventually requeened, but this was
unusual as Poly wasn't doing regular requeening in this era, but rather
managing supercedure cells.  Folks just got fed up with dealing with this
hive and ordered a commercial queen.)
 
All you had to do was take off the top cover and you could *hear* the
difference---a slight amplification and an ascending note of buzzing.  I
never was stung while working any of the other hives.  Good old #4 always
managed to get me or make a good try for it.
 
I think it's genetics.
 
Jane B.