[Hannah LS (OP)]

Bill says:

I spent all my working life in substations with relatively high electric and magnetic fields, and discussion with colleagues noticed a preponderance of girls in our offspring. Has any investigation taken place on this issue? We (a group of 20 or so) may just be a coincidence but it would be interesting to do a wider study.

What do you think?

[evan_au]

I work in telecommunications, and our technical director made a similar observation, many years ago: Engineers tended to have more daughters than sons.

I guess that genetically, girls are more robust than boys, as they have a fully redundant set of chromosomes, while boys have 1 chromosome that doesn't have a backup copy.

[Bored chemist]

It may not be anything to with exposure to electric fields.
https://personal.lse.ac.uk/kanazawa/pdfs/JTB2005a.pdf

[syhprum]

Has adjustment been made for the number of children I would expect engineers on average to have more children due to their higher than average income with some of them born when the parents are older.
this could skew the mail/female ratio

[yor_on]

Hmm BC?

" Baron-Cohen’s theory leads to the prediction that men (and women) who possess more systemizing brains should have more sons than daughters, while women (and men) who possess more empathizing brains should have more daughters than sons. We present the analysis of the 1994 US General Social Survey which empirically supports our prediction. "

Are you suggesting that engineers are of a more 'female' trait?
And looking at this 'empathy' thingie?

Is it then presumed that emphaty must be a female disposition?

[Bored chemist]

Are you suggesting that engineers are of a more 'female' trait?

Nope,
I'm suggesting that looking at the numbers shows that there are differences which are independent of (or have common cause with) occupation.

[yor_on]

Ah, okay. The text threw me a little there, but you're thinking of the statistics primarily.