People easily disgusted by body odours seem to prefer authoritarian leaders and were likelier to support Donald Trump, an unusual study into the origins of ideology suggested Wednesday.
The seemingly obscure link, it said, may be rooted in a deep-seated instinct to avoid disease -- whether in individuals whose smell suggests they are germ-carriers, or "unfamiliar" people such as immigrants or minorities.
The study results "contribute to the growing evidence that contemporary social attitudes may be rooted in basic sensory functions," the researchers wrote.
In two online surveys, the team asked people in several countries a series of questions to determine their level of "body odour disgust sensitivity" (BODS), as well as their position on the political spectrum.
They were looking for signs of "right-wing authoritarianism" -- which study author Marco Liuzza from Italy's Magna Graecia University summarised as an attitude "promoting aggressive policies towards groups perceived as deviant or threatening the traditional values".
Analysis of the data revealed a "solid connection" between how strongly people reacted to body smells and their desire for a leader that can keep groups of people "in their places", said co-author Jonas Olofsson of Stockholm University.
In a third test, with American participants, the researchers looked for a correlation between BODS and support for Trump -- who they said "was described as having a particularly authoritarian message".
The study, published in the Royal Society journal Open Science, was conducted when Trump and Democrat Hillary Clinton were rival candidates for the presidency.
The results "showed that people who were more disgusted by smells were also more likely to vote for Donald Trump than those who were less sensitive," said Olofsson.
"We thought that was interesting because Donald Trump talks frequently about how different people disgust him ... It fits with our hypothesis that his supporters would be more easily disgusted themselves."
Disgust is a crucial survival tool that helps humans avoid potential health threats lurking in foul-smelling, rotting flesh, for example.
It can also be triggered by non-infectious stimuli, including by people who "deviate" from the societal norm, whether it be physically, morally or with their sexual preferences.
Smells listed in the questionnaires included breath, sweat, feet, faeces, urine and gas -- the participants' own and that of strangers.
Political questions tested a participant's stand on issues such as abortion, pornography, religion, and morality in general, as well as whether they intended to vote for Trump or not.
Theorising on the connection with BO recoil, Olofsson proposed that living in an authoritarian society "reduces contact among different groups and, at least in theory, decreases the chances of becoming ill".
The study of authoritarianism was important, added the team, "as it appears relevant to explain current political trends."
"Our findings highlight body odour disgust as a new and promising domain in political psychology research," they wrote.
In the future, added Liuzza, this knowledge "might inform policies to prevent ethnocentrism".