Most of us are a bit uneasy about the idea that somebody can influence our thinking without our awareness. We are bombarded by enough obvious persuasive messages as it is, without having to worry about messages we don’t even notice.

Although this example is not exactly subtle, and one wonders if it in fact has any effect on behavior, the PETA brick, purchased at the San Diego Padres’ PETCO stadium, spells out “Boycott Petco” if you just look at the first letter of each word.  

The study of subliminal messages (messages that are “sub” or below our “limin” or threshold of awareness) has a long history. Back in 1956, social psychologist James Vicary claimed that he could boost sales of movie popcorn and Coca Cola by flashing the messages “eat popcorn” or “drink Coca Cola” during a movie. In spite of Vicary’s later confession that he made up his data, not to mention the failure of scientists to replicate his results, many people still believe that subliminal messages work. Americans spend more than 50 million dollars a year on subliminal tapes for self-improvement, and much controversy has surrounded subliminal or back-masked messages in music.

More recently, Vokey has distinguished between a person’s objective and subjective thresholds for awareness [1]. A person responding to a stimulus at the objective threshold will do no better than chance in identifying its presence, and these stimuli appear to have no impact on behavior. However, a stimulus falling between a person’s objective and subjective thresholds will be detected at better than chance levels, and does appear to have the ability to influence behavior.

Ran Hassin and his colleagues at the Hebrew University of Jerusalem have added additional and disturbing information to our understanding of subliminal messages. These researchers flashed an image of the Israeli flag on a monitor to half of their participants. Although the participants were unaware of the flag image, those who saw it shifted their political views to more moderate positions. This shift extended to actual voting patterns, as the flag-exposed participants were more moderate in their voting in a real election.

I’m not saying moderation is a bad thing, but it strikes me as creepy to think that my beliefs and behavior could be so easily manipulated. It’s also very interesting that the flag image produced a centrist result for both right and left-wing extremists. Why the flag image would have this effect is currently unknown, but I think we can expect some follow-up research on this topic.

1.  Vokey, J. R. (2002). Subliminal messages. In John R. Vokey and Scott W. Allen (Eds.), Psychological Sketches (6th Edition, p. 223-246), Lethbridge, Alberta: Psyence Ink.

2.  Hassin, R.R., Ferguson, M.J., Shidlovski, D., & Gross, T. (2007). Subliminal exposure to national flags affects political thought and behavior. PNAS, 104,19757-19761; published online before print as 10.1073/pnas.0704679104


2 Comments

Ranger_Rick · January 11, 2008 at 7:03 pm

I think subliminal messages are interesting, however, when the world is suffering from a god delusion of enormous dimensions subliminal messages, well, er, really don’t add up to much.

brizdaz · February 5, 2008 at 4:13 pm

Here’s an example;take the world famous Virgin logo.If you turn it slighty to the left so that where the underline and tail of the g form an X,you’ll also notice the V forms a slightly hidden S and the i,r and part of the g form a broken capital E,spelling the word SEX.
So you have Sex/Virgin in one word.Very clever Mr.Branson.

Comments are closed.