I also have theory that a higher percentage of ATC graduates are left-handed.
Certainly my experience of working in several en-route environments would support that theory. In fact in one straw poll of the 25 ATCOs on duty 13 were left handed and with that result we then had the positions set up for left handers much to the chagrin of the righties.
It is certainly something that I checked with all my trainees over the years. There do seem to be a bigger proportion of lefties in ATC than the average would suggest, but only on the area side of ATC. Approach controllers are mainly all right-handed and I never noticed any bias in tower controllers.
Also graduates with science-oriented degrees, where there are "black and white" solutions to problems, seemed less able to cope with "out of the ordinary" scenarios.
Mind you, I could be a tad biased, as I'm left-handed and not a science graduate. Wasn't too shabby at controlling either, but that's probably debatable.
<- he's a leftie!
On the beach