Women scientists are being held back in their careers by a combination of traditional gender roles in the home and a negative bias in the workplace. This is the conclusion of a new report by researchers at the European Molecular Biology Organization (EMBO), published in the journal EMBO Reports. The report analyses the factors influencing the success of women applicants to two EMBO grant schemes: the Long-Term Fellowship (LTF) Programme, which funds post-doctoral research, and the Young Investigator Programme, which targets scientists who have recently set up their first independent laboratories. Statistics show that women are 20% less successful than men in applying to these programmes. This is in spite of the facts that EMBO has a clearly stated commitment to gender equality, and that the organisation receives roughly equal numbers of applications from men and women. To test whether this outcome was due to unconscious gender bias, EMBO gender-blinded the selection committee for two rounds of applications in 2006, removing all references to gender from the applications, letters of recommendation and interview reports. However, the difference in success rate remained unaffected by these measures. The researchers then carried out a detailed analysis of the applicants' publications, which revealed that on average, women publish fewer scientific papers than men, and the gap between the sexes widens as careers progress. This could have been the source of the bias towards male applicants in the selection committee. To find out why women are producing fewer publications, the scientists carried out surveys of applicants to the EMBO programmes. These revealed that women were more likely to move for their partner's career than men, something which provides part of the answer to the question of why women publish fewer papers. If a woman follows her partner, she is less likely to find a laboratory which suits her expertise and expectations. 'They publish fewer papers owing to working in a sub-optimal environment,' the researchers write. Women's career prospects are dealt a further blow by the fact that they take on the majority of childcare responsibilities, resulting in more career breaks for parental leave and fewer hours worked. 'We believe that our data offer some explanation for why women publish less and why they might be slower to advance - quite simply, because women on average have less time available at work and have a greater burden to carry outside the laboratory,' the authors write. However, the paper notes that these traditional gender roles are not the whole story. The surveys also revealed that while 49% of male Young Investigator applicants had a mentor, for women the figure was just 32%. 'Therefore, more women at the group-leader level miss out on the valuable support and networking that a mentor has to offer,' the article reads. Furthermore, many women reported that their supervisors became less supportive when they had children. According to the researchers, these workplace factors combine with traditional gender roles in the home to create a 'harmful mix which leads to women being less successful than men over the course of their careers'. The authors call on employers, policy makers, scientists and society to 'consider whether we can afford to lose such a large number of trained specialists from the workforce'. 'We need to ensure that men and women who want to have families are not prevented from also having careers and contributing to society in every way that they can,' the paper concludes. 'This can only be achieved by a significant change in the way that society and individuals think about the roles of men and women, and by taking positive action to improve the working conditions and available support for both women and men at all stages of their careers.'