A paper in the Journal of Evolutionary Biology looks at why the number of male invited speakers at a key biology congress exceeded those of female invited speakers. Women were under-represented even when taking into account that they are a smaller proportion of the pool of potential speakers. On delving deeper into the data from the 2011 congress, they found women were under-represented as invited speakers, not because men were invited proportionally more than women, but because men accepted invitations more often. They propose two major reasons for this. Firstly, uneven sharing of family/baby responsibilities. Secondly, women are less likely then men to self-promote. Readers can test their own gender bias at this link.