Women in the UK are being held back in the workplace by a lack of confidence, according to a poll by YouGov for Oxford Open Learning Trust.
The survey, which questioned more than 2,000 people, found that more than four in ten (44%) of female respondents said they agreed with the statement: "Lack of confidence in my skills has led me to NOT apply for a new job or promotion before."
The research revealed that the top three barriers women listed for not taking further qualifications was the cost with 35% saying they cannot afford it, feeling they were already sufficiently qualified (32%), and time (29%).
YouGov said women were more than twice as likely as men to say there was nothing that would motivate them to take further qualifications (14% vs 6%).
"These results demonstrate the importance of confidence in the workplace and an advantage that men have had for decades, if not centuries," said Dr Nick Smith from the Oxford Open Learning Trust.
"But there is no room for complacency for either sex. It is vital for all of us to refresh and enhance the skills that we bring to our careers."
But the survey also found that women were more likely to feel they had sufficient literacy and numeracy skills for their current role.
Some 96% of female respondents agreed with the statement "I feel that I have sufficient numeracy skills for my current job", compared to 90% of men.
Additionally, 95% of women believed they had sufficient level of literacy for their role - again, higher than their male counterparts (91%).
The figures come after separate research from the Professional Boards Forum found that the number of women on FTSE 100 boards increased to 21.6% in May.