Herding the followers

HITLER and Mussolini both had the ability to bend millions of people to their fascist will. Now evidence from psychology and neurology is emerging to explain how tactics like organised marching and propaganda can work to exert mass mind control.

Scott Wiltermuth of Stanford University in California and colleagues have found that activities performed in unison, such as marching or dancing, increase loyalty to the group. "It makes us feel as though we're part of a larger entity, so we see the group's welfare as being as important as our own," he says.

Wiltermuth's team separated 96 people into four groups who performed these tasks together: listening to a song while silently mouthing the words, singing along, singing and dancing, or listening to different versions of the song so that they sang and danced out of sync. In a later game, when asked to decide whether to stick with the group or strive for personal gain, those in the non-synchronised group behaved less loyally than the rest (Psychological Science, vol 20, p 1).

Psychologist Jonathan Haidt at the University of Virginia in Charlottesville thinks this research helps explain why fascist leaders, amongst others, use organised marching and chanting to whip crowds into a frenzy of devotion to their cause, though these tactics can be used just as well for peace, he stresses. Community dances and group singing can ease local tension, for example - a theory he plans to test experimentally (Journal of Legal Studies, DOI: 10.1086/529447).

Meanwhile, the powerful unifying effects of propaganda images are being explored by Charles Seger at Indiana University at Bloomington. His team primed students with pictures of their university - college sweatshirts or the buildings themselves - then asked how highly they scored on different emotions, such as pride or happiness. The primed students gave a strikingly similar emotional profile, in contrast with non-primed students (Journal of Experimental Social Psychology, DOI: 10.1016/j.jesp.2008.12.004).

Interest in the idea of a herd mentality has been renewed by work into mirror neurons - cells that fire when we perform an action or watch someone perform a similar action. It suggests that our brains are geared to mimic our peers. "We are set up for 'auto-copy'," says Haidt. Interest in the idea of a herd mentality has been renewed by research into mirror neurons

Neurological evidence seems to back this idea. Vasily Klucharev, at the Donders Centre for Cognitive Neuroimaging in Nijmegen, the Netherlands, found that the brain releases more of the reward chemical dopamine when we fall in line with the group consensus (Neuron, vol 61, p 140). His team asked 24 women to rate more than 200 women for attractiveness. If a participant discovered their ratings did not tally with that of the others, they tended to readjust their scores. When a woman realised her differing opinion, fMRI scans revealed that her brain generated what the team dubbed an "error signal". This has a conditioning effect, says Klucharev: it's how we learn to follow the crowd