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Monkeys and Cognitive Dissonance
Hugh Pickens writes "People deal with cognitive dissonance — the clashing of conflicting thoughts — by eliminating one of the thoughts. Psychologists have suggested we hone our skills of rationalization in order to impress others, reaffirm our "moral integrity" and protect our "self-concept" and feeling of "global self-worth." Now experimenters at Yale have demonstrated that other primates employ the same psychological mechanism. In one experiment, a monkey was observed to show an equal preference for three colors of M&M's and was given a choice between two of them. If he chose red over blue, his preference changed and he downgraded blue. When he was subsequently given a choice between blue and green, it was no longer an even contest — he was now much more likely to reject the blue. Rationalization is thought to have an evolutionary utility; once a decision has been made, second-guessing may just interfere with more important business. "We tend to think people have an explicit agenda to rewrite history to make themselves look right, but that's an outsider's perspective. This experiment shows that there isn't always much conscious thought going on," said one researcher."
I haven't worked in the vision lab for a few months (and I did only work with humans), so maybe I'm getting rusty :) but I thought that it would be easy for even a dichromat to distinguish between red and blue? I mean, what single cone, if disabled, would produce a difficulty in distinguishing red from blue?
Did you mean maybe that these monkeys diverged from humans' evolutionary branch before the red and green cones differentiated from the older, yellow cone? If that were the case, they still should have no trouble distinguishing red from blue.
Mods - if you must agree with the parent, rank it "Funny" or at least "Insightful"... but there is nothing informative about it.
Everything is easy when you don't understand the problem.
Not that I am in any way supporting or rejecting the claims made in the study, but your criticism is probably unfounded**.
.05), and designated the items within each triad as choices A, B, and C (choices were specific to each individual monkey); although there were no significant differences in preferences across the three M&M colors within a triad, we conservatively used each subject's least preferred color of the three (i.e., the one the monkey took longest to obtain during preference testing) as option C.
The M&M (and sticker choices) were different across subjects, so it is unlikely that a systematic bias could result from visual perception of the items. The M&M choices chosen for the subjects were determined by relatively equal preference in a pretraining phase of the experiment. Given the fact that they find an effect, it's unlikely that it's due to an inability to tell the items apart.
Specifically:
We first assessed the monkeys' existing preferences for M&M's of different colors by timing how long they took to retrieve individual M&M's. For each monkey, preferences for at least nine different M&M colors were assessed. As each preference test began, the monkey was inside its home cage, just outside a testing chamber, and was allowed to watch as the experimenter placed one colored M&M on a tray outside the other side of the chamber. The door to the testing chamber was opened, and the monkey was allowed to enter when it wished to retrieve the M&M. We measured how quickly the monkey entered the testing chamber to retrieve the M&M. Preferences for each color were assessed across 20 trials per monkey; trials for each color spanned two experimental sessions.
After preference testing, we performed analyses of variance to determine whether each monkey had statistically significant preferences. We identified triads of equally preferred colors (all ps >
**By the way, I've been reading your slashdot comments for quite some time, and so don't take this as a personal affront or anything. =) I think you're probably one of the better scientist/posters on the site. =)