In a classic psychology experiment by John Bargh of New York University students were shown a set of words associated with the elderly but not including the word 'elderly' - wrinkled, forgetful, blad grey, florida. These students were then asked to move to another room and they were timed in contrast to another set of students with randomly selected words. It was found that the suggestion of elderly caused the students to walk slower (!) This is known as the Florida Effect. Whilst most of the time we think that the toughts we are having are nobody else's but our own it is very easy for thoughts to cause behaviour because the mechanisms of our brain are automatic and they can be manipulated without our knowledge. In another experiment voters were measured according to votes to support increases in school funding depending on the location of the voting station. Those located in schools were found to have more votes for increased funding.
This also works in reverse it was also found in an experment that when students were forced to walk slower they were 'primed' to think about the elderly.
Thoughts can be suggested, voting actions can be inflenced by images, locations, it is important that more people know and understand the way the brain works before more sinistergroups start to manipulate our thoughts.
From 'Thinking fast and slow' by Daniel Kahneman.