The best degree results are coming from mature students who began their degrees with no A levels, a study at Plymouth University has found, writes Aisling Irwin.
The worst results are from male students who began their degrees without A levels between the ages of 18 and 20, the British Psychological Society heard this week.
The findings are some of the first to come from the student data that universities have recently been obliged to return to the Higher Education Statistics Agency.
Most universities have not analysed their own data in depth. But at Plymouth, psychology researchers studied the degree results of 7,000 students who graduated over the past five years.
The researchers said they were surprised to find that the over-25s, who started with access courses, BTecs, Higher National Diplomas or sometimes no qualifications at all, fared better by a quarter of a degree grade, than 18 to 20 or 21 to 25-year-olds.
Their average grade was a 2.1 compared to a 2.2 for the other groups. While mature students did better if they started without A levels, the other ages did better if they started with A levels.
Sherria Hoskins, PhD student who did the research with Stephen Newstead, professor of psychology, said: "Older students may be coming in with more intrinsic motivation, studying for the enjoyment and trying to understand and not just memorise and regurgitate. The message is that mature students are not lowering the standards and may even be raising them."
The research also found that firsts were equally distributed between the genders. This differs from Oxbridge research showing that firsts are more common among men.
Phil McGeevor, a deputy registrar at South Bank University, who has studied degree results, said that the over-25 group would contain a wide variety of ages and types, including, for example, older women discouraged from higher education when they were younger despite being bright.
The success of the non-A level group was therefore probably "an indicator of something else rather than the qualifications".
Ms Hoskins called for other universities to examine their databases to see how widely the Plymouth results could be extrapolated.