Women may be less prepared than men to vote with their hearts when it comes to independence, new research has found.

Higher levels of uncertainty about the consequences of a yes vote also appears to be a factor in explaining lower levels of support among female voters, according to ScotCen Social Research.

Opinion polls and surveys have shown that women are significantly and persistently less likely to vote for independence.

The Scottish Social Attitudes survey for 2012 recorded support for independence at 20% among women, compared with 27% among men, while results from some of the major polling groups since February 2013 have found a gender gap in the proportion of people stating they will vote yes of between 1% and 22%.

ScotCen's latest research paper calls into question some of the explanations which have been put forward to explain the gender split.

Its findings suggest that empirical evidence to support the idea that the women's priorities are substantially different from men's appears relatively weak while the notion that a lack of focus on gender equality is something that puts many women off is also open to question.

ScotCen also questioned the explanation that First Minister Alex Salmond's relatively lower popularity rating among female voters was a key issue when it comes to lower levels of support for independence in this group.

"An obvious rebuttal to the argument that Salmond is the main cause of the gender gap on independence is to point out that this gap existed even during the period when the SNP was led by John Swinney," the research stated.

"So while Salmond may not be the yes campaign's best asset in terms of pressing their case with women specifically, findings over a longer timeframe suggest that the gender gap on independence would exist with or without him."

ScotCen also found no evidence for women feeling "less Scottish" than men while women are "no more negative than men in their expectations of the consequences of independence".

Data from the Scottish Social Attitudes survey did find that women were "significantly more likely" to say they do not know what the consequences of independence will be.

"This greater uncertainty about its consequences does appear to be a factor in explaining why support for independence is lower among women," the research said.

"Women's responses to questions posing different possible outcomes in terms of the impact of independence on the standard of living suggest that they may be less prepared to vote with their 'heart' and may need more convincing on the practicalities.

"Rather than indicating that women are more 'feartie', these findings can be read as reflecting a more realistic and pragmatic response among women to the numerous uncertainties of the current debate."

Commenting on the findings, a spokesman for Yes Scotland said: "It is clear that more women are currently undecided on how they will vote in the referendum and Yes Scotland is confident that as we continue to present our case on the benefits of independence, women in Scotland will realise that a yes vote secures the best deal for them and their families.

'Westminster isn't working for Scotland and the impact of the welfare cuts and policies, such as the bedroom tax, are making many - women as well as men - realise that only independence offers the chance of a fairer, more prosperous Scotland."

Labour MSP Patricia Ferguson said: "The consistent gender gap clearly shows women want answers on the fundamentals such as our currency, EU (European Union) membership and levels of debt.

"The SNP need to come clean on the issues as the women of Scotland want certainty about these things and deserve to know what they are voting for."

Liberal Democrat MSP Alison McInnes said: "The latest poll shows that the SNP are making no headway, despite their recent charm offensive.

"Women have a key role to play in the independence debate, but when they pose tough questions they deserve straight answers.

"This group of voters is demonstrating it will take more than vague promises of jam tomorrow to secure their votes."

Scottish Conservative deputy leader Jackson Carlaw said: "Anyone who's examined the SNP's financial plans for a separate Scotland will be extremely concerned about Salmond's independence enigma.

"And that's only from what we know - it's what the SNP hasn't told us where more fear should lie.

"Nicola Sturgeon has made no secret of her desire to get more women on board for breaking up Britain.

"Judging by this survey, if anything, she's had a negative impact."