Just the thought of earning less than their wives made men in the US switch their vote from Hillary Clinton to Donald Trump.

The threat to masculinity caused men to change who they would vote for in the next presidential election, a recent study revealed.

The experiment was carried out by Fairleigh Dickinson University in which a survey with one unusual question asked married and cohabitating men if they earned less or about the same as their spouses.

Thought of a Woman President Rattles Male Voters in New Jersey via /r/politics @marecko https://t.co/o2UkfeWCId pic.twitter.com/9XKzaFRiVP — Politics News (@recentpolitical) March 30, 2016​

The question was asked, so it would get men to think about potential risks to their gender roles. Discussing salaries has always sparked huge debate in relationships and society as a whole — and this time was no different.

Just asking the question on spousal income led to an enormous shift in men's preferences regarding the up and coming US presidential elections.

For those respondents who were not asked about spousal income until later in the survey, they preferred Hillary Clinton over Donald Trump.

On the contrary, men who were asked about spousal income earlier in the survey preferred Trump.

Spousal income however, has no effect on the presidential election or even a direct link, yet that did not matter. The question on spousal income also had no impact on how men responded to the rivalry between Trump and Bernie Sanders.

© REUTERS / Scott Audette (L), Javier Galeano (R) A combination photo shows Republican US presidential candidate Donald Trump (L) and Democratic US presidential candidate Hillary Clinton (R)

The results of this study are not 100 per cent unique, as other research shows that men who perceive a certain threat to their masculinity become more likely to stress the role of household decision maker — which even pushes some to the conclusion that they need to purchase an SUV to reaffirm this role.

There was some hope though, among some groups — such as young liberal men — that the gender role threat led to greater support for Clinton.