I was very pleased to see the issue of sexism in science being raised in Steven Swinford's article Sunday 11th May with the identification of the "hidden brain drain". There are many factors involved in why women leave science. For example, the UK Resource Centre for Women in Science, Engineering and Technology (SET) reports that in SET the salaries are still gender biased and  the National Science Foundation in the US has reported that having children is negatively related to women's chances for employment in tenure-track positions.  Whether lack of tenure for mums in science is a woman's choice, for example due to the very long working hours, or the employee's choice, is somewhat irrelevant as we are losing a talented proportion of the scientific workforce.  In other industries, recruitment, retention and development of the most talented people in the workforce - including women - has become a priority, but in many science disciplines there has been a reluctance to change working practices. 

However, science is a very broad discipline and different areas of science deal with this issue in different ways.  For example, the Institute of Physics has a professional group which not only supports women in research and academia, but educates at primary and secondary school level to encourage women to enter the sciences.  This is not true of other science disciplines and we should be seeing all scientific societies taking an active role in changing conventional working practices to help establish a good work-life balance, not just for women, but for all scientists.  This would not only benefit scientists, but also society and our economy, reducing any type of brain drain, not just the "hidden" one.