I’ve had some truly fascinating emails in response to this column on PMT. I had forgotten completely about this BMJ paper, from 1953, which you can view for free if you register. The first author is Katharina Dalton, who is famous for advocating progesterone to ‘treat’ PMT, and which is now recognised as being non evidence based. I had this very interesting reply, which the author is happy for me to reproduce:

“As a medical student in the 50s while reading the article in the BMJ by Katherina Dalton on PMT, it dawned on me that that the study was done at the boarding school I attended. This purported to correlate the premenstrual phase with weekly grades.

There were at least 2 problems with this:-
1. In the lower school the work done that week was likely to be marked and assigned to the grade that week.
Higher up the school assignments were likely to be given longer to complete and marked later, ie there may be 2-3 weeks between completing the work, marking and entering the grade for a week.

2. Timing of periods
After Sunday morning service a “black book” was placed in the common rooms for girls to enter dates of any period that occurred that week..
Few followed this conscientiously, however if by the end of term no dates had been entered an embarrassing visit to the san to see the doctor ensued which was to be avoided. Many dates were made up.

There was a third category of tidiness assessed by the house matron. I have no idea how this was done.”

Also worth reading is this paper in the Proceedings of the Royal Society of Medicine – a salutory tale. Marcus du Sautoy I think summed up the difficulty with seeing patterns where none exist in his Christmas Lectures a few years ago. The kids were asked to identify a series of primes, or doubling ratios – no problem. They were then asked to find a harder pattern in a set of numbers; what was it? The answer: the winning numbers from last weeks’ lottery.