Scans of 90 students' brains at University College London (UCL) uncovered a "strong correlation" between the thickness of two particular areas of grey matter and an individual's views.
Self-proclaimed right-wingers had a more pronounced amyg-dala - a primitive part of the brain associated with emotion - while their political opponents from the opposite end of the spectrum had thicker anterior cingulates.
The research was carried out by Geraint Rees, director of the UCL Institute of Cognitive Neuroscience, who said he was "very surprised" by the finding, which is being peer reviewed before publication next year.
The study was commissioned as a light-hearted experiment by actor Colin Firth as part of his turn guest editing BBC Radio 4's Today programme but has now developed into a serious effort to discover whether we are programmed with a particular political view.
Professor Rees said that although it was not precise enough to be able to predict someone's stance simply from a scan, there was "a strong correlation that reaches all our scientific tests of significance".