The positive discrimination part is understandable I guess, but like you Keith, I'm a bit puzzled by the "civilising effect" and also by the Saturday night meals.
On Signy in the mid 80's every Saturday was as formal a meal as we could manage. The gashman for the day would act as waiter for every-one else and lob the wine for the evening. We didn't use white tablecloths as freshwater was in short supply and unless they were thrown away, it would be wasteful to use them.
Loutish behaviour? Well blokes together behave differently to when there are women about. My last summer on Signy 86-87 was the first time BAS had sent women down South, a token one turned up on base from first call I think and then there were another two who overwintered (87) - but I never met them as I left mid-season. Did behaviour change? not that I recall - less swearing when females were about, but that happens anywhere, and of course women introduce other tensions that were not there before.
I just wonder if Mrs. Lewis's stay at Halley wasn't coloured by the fact she was there immediately after the winter and the culture shock that it brings to the winterers. Maybe times have changed with British culture becoming more "laddish" and that has been taken South with recent recruits, but I don't know. But whatever other arguments for more women being specifically recruited there are, the behaviour modification one is certainly interesting and as puzzling to me as it is to Keith.