The analysis of more than 734,000 A-level entries was carried out by Jannette Elwood, from the Institute of Education at London University. She claimed papers set by the Associated Examining Board (AEB) and University of London Examinations and Assessment Council (ULEAC) were "female-friendly" in choice of text, style of questioning and inclusion of authors.
Her research, based on the 1993 Inter-Board Statistics covering England, Wales and Northern Ireland, shows that boys perform better than girls at English literature, achieving more of the top three A-level grades.
But Ms Elwood said with female candidates taking A-levels set by the AEB and ULEAC the pattern reversed and girls achieved more of the higher grades.
She said English literature papers set by the two boards were "less harsh and more inviting to provide personal responses, rather than a straightforward analytical approach, which suits girls."
Tony Smith, chief executive of ULEAC, said: "I am not aware that we have a gender bias towards females, but we definitely have a strong commitment to an equal opportunities policy. I certainly expect our question papers to be free of a gender bias in the opposite direction."
George Turnbull of the AEB, said: "We are neither female-friendly, nor male-friendly. We are student-friendly. All students need to be able to understand the questions."
The GCSE has tended to favour girls because they are more disciplined at completing coursework and for several years they have gained better results than boys.
The new research follows another study by the National Consortium for Examination Results - featured in a BBC1's Panorama this week - which disclosed that for the first time girls outperformed boys at A-level across all grades this year. Boys, however, still gain more of the top grades.
According to the NCER research, this year, 41 per cent of 1.57 million GCSE entries from boys were grades A to C compared with 51 per cent from the 1.63 million female candidates.
Boys, however, have tended to catch up in the two years between GCSE and A-level as they mature emotionally and acknowledge the value of education.
According to Ms Elwood the lead held by boys at the top three grades at A level has been whittled down to just 0.8 per cent. She is investigating performance in English literature, maths and physics to ascertain whether the A-level is equally fair to boys and girls.
First findings show that at grades A to C, boys were 1.8 per cent ahead in English literature despite comprising just 30 per cent of entries, while girls outperformed boys in the male-dominated maths and science. At grades A to C girls were 0.4 per cent ahead in maths and 0.9 per cent in physics.
However, at grades A and B, boys led in all three subjects with a 2.5 per cent gap at English literature, 1.8 per cent difference in maths and 0.4 per cent in physics.