[LeoPanthera]

The “surrounded by electronics” explanation really need a citation. It doesn’t make sense to me. Nothing in proximity to the pilot emits any kind of radiation - the radio antenna is not in the cockpit.

The higher dosage of solar/space radiation due to the altitude is surely the correct explanation.

[phyller]

Interestingly, there is a belief in military pilot communities that pilots will have far fewer boys than girls. Two close relatives of mine are military pilots, and my observations have confirmed this. From individual families we know, to officer neighborhoods on base that have an unusually high proportion of girls. It's still anecdotal of course, but very interesting.

Apparently there have been a few studies, but with questionable rigor. For example http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.603...

[loceng]

It's one of those things where I believe only mathematical/physics model could potentially show us answers, as that's the only way we'd ever be able to get "exact" resolution of what's going on between interactions. Whether we can ever model these systems to be as refined as reality is impossible to know - however perhaps we should start trying and see if what we are able to model shows anything that could perhaps help us direct more inquiry into; it makes me think of the Periodic Table, and how we were able to discover new/missing/unknown elements simply by ordering and seeing gaps in the model.