Ann Hibner Koblitz and Neal Koblitz, reviewing In Code: A Mathematical Journey by Sarah and David Flannery (Books, 色盒直播S , November 10), claim that "there is no excuse for allowing the severe under-representation of women in the mathematical sciences to continue", an issue about which Sarah Flannery herself says nothing.
Mathematical ability is gender linked, with a balance of males that greatly increases towards the upper end of the distribution. Taking a level of ability reached by only one in 10,000 of the population, for example, boys outnumber girls by about 13 to one.
This, no doubt, is the main reason why in Ireland "women... make up less than 10 per cent of the roughly 120 lecturers with doctorates".
John Radford Emeritus professor of psychology University of East London