Sir: You report (18 November) on research that suggests that nurture rather than nature is responsible for the variation in people's pain thresholds.
Years ago I lived in Montreal, when French Canadians were still famous for producing large families. Ten or more children was common. My dentist there told me he could always tell whether a woman patient had been the eldest daughter in her family. The eldest daughter, he said, did not feel pain that would have others howling.
He attributed this to the fact that they were bred to be concerned and responsible for others, to the exclusion of self, from a very tender age.