A person's sense of smell can predict how they will vote in political elections, a new study suggests.

Researchers at Stockholm University in Sweden found that the way people react to body odor in particular is a psychological indicator of their political preferences.

US participants were given a survey that paired questions about smell with questions about which candidates they planned to vote for in 2016.

The results revealed that people who were more disgusted by certain odors such as urine and sweat were also more likely to vote for Donald Trump than those who were less sensitive.

A survey by researchers at Stockhold University found that US participants who reported higher levels of disgust with bodily odors were more likely to vote for Donald Trump

Sense of smell, or olfaction, has been studied extensively by psychologists, revealing that scents have the power to influence human behavior on an instinctive level.

For this study, the Swedish researchers used a scale for participants to rate their levels of disgust for body odors, both their own and others.

An extensive survey was distributed online in several different countries with questions from the scale alongside questions about participant's political views.

In the US, the researchers added questions regarding how each participant planned to vote in the 2016 presidential election.

According to lead researcher Jonas Olofsson, who studies the link between scent and psychology, the survey results show that from country to country people who easily disgusted by body odors like sweat and urine are also drawn to authoritarian political leaders.

The researchers said this might come from a deep-seated instinct to avoid infectious diseases.

'There was a solid connection between how strongly someone was disgusted by smells and their desire to have a dictator-like leader who can suppress radical protest movements and ensure that different groups "stay in their places."

'That type of society reduces contact among different groups and, at least in theory, decreases the chance of becoming ill,' Olofsson said.

Disgust is a basic emotion that helps humans survive by protecting from dangerous and infectious things that should be avoided.

A previous study by psychologist Johan Lundstrom, PhD, found that the brain processes body odors differently from other smells because of the same evolutionary factors.

Brain scans collected in the study showed that true body odor scents from items like sweaty T-shirts fired up different brain pathways than artificial odors.

The body odors were found to light up regions of the brain used in recognizing familiar and frightening stimuli.

'We believe that throughout evolution, these body odors have been tagged as important stimuli, so they've been given dedicated neural networks to process them,' Lundstrom, a faculty member at the Monell Chemical Senses Center in Philadelphia, said in an article for the American Psychological Association.

Another study by Rice University found that there are individual differences in a person's sensitivity to body odor that are linked to their style of social communication.

The lead researcher Denise Chen, PhD, asked female subjects to sniff three shirts, two that had been worn by strangers and one that had been worn by the subject's roommate.

The study found that women who correctly picked out their roommate's scent scored higher on tests of emotional sensitivity.

In other words, people who were more sensitive to social smells were also more sensitive to emotional signals.

We thought that was interesting because Donald Trump talks frequently about how different people disgust him. - Dr Jonas Olofsson, lead researcher

The study by Stockholm University was designed with previous research on the connection between evolutionary and social factors in mind.

The researchers went into the project with a theory that there would be a connection between feelings of disgust and how a person would want society to be organised.

They thought that people with a strong instinct to distance themselves from unpleasant smells would also prefer a society where different groups are kept separate.

With regard to the US results, Olofsson said he and the other researchers were not surprised to find that people who said they planned to vote for Trump were also more likely to be disgusted by certain odors.

'We thought that was interesting because Donald Trump talks frequently about how different people disgust him,' Olofsson said.

'He thinks that women are disgusting and that immigrants spread disease and it comes up often in his rhetoric.

'It fits with our hypothesis that his supporters would be more easily disgusted themselves.'

However, the findings go against those found in a 2016 study by researchers in Beijing, China, that suggested that the more sensitive a person's olfactory system was, the larger their social circle would be.