In a meta-analysis of peer-reviewed procedures during grant applications by researchers Rudiger Mutz, Hans-Dieter Daniel and Lutz Bornmann at the Professorship for Social Psychology and Research on higher Education at the Swiss Federal Institute of Technology in Switzerland discovered a bias against women. They concluded that the reason for this gender bias is unknown. But, one of the factors could be that fewer women principal investigators apply for grants. Other explanation offered by them is that more men occupy high ranking positions, i.e., "decision-making positions" than women in institutions. They also discussed about the ways to avoid gender bias and their suggestion is to mask applicants gender.
Another study by Gunnel Gustafsson, Carl Jacobsson and Carolyn Glynn at the Swedish Research Council in Sweden analyzed all 17,000 grant applications to their council during 2003-05. They found little evidence for gender bias and reported that the success rate for receiving grants were roughly the same for both the genders. But still they discovered other discrepancies such as less success rates for women with fellowships to be post-docs, long term grants for prominent research environments and in nearly all types of grant in the field of medicine. The Swedish researchers ignore the reason for gender bias mentioned by their counterparts from Switzerland. These researchers attributed the low success rate for women in scientific careers to "career age" - the number of years that have passed since applicants earned their PhDs. Success rate increased with increase in career age and on an average women have less career age than men.
However, there is a widespread acknowledgment of gender bias in scientific careers. The US National Science Foundation in its review on gender differences in the careers of academic scientists, concludes: "Taken as a whole, the body of literature we reviewed provides evidence that women in academic careers are disadvantaged compared with men in similar careers. Women faculty earn less, are promoted less frequently to senior academic ranks, and publish less frequently than their male counterparts." other studies also pointed to similar problems. This suggests that it would be necessary to carry out international comparative study to reach a conclusion.