Just when you thought people couldn't get any sillier or more confused, psychologists uncover yet another innate foible. This one is called "choice blindness," and it refers to the ways in which people are utterly blind to their own choices and preferences. We think we want X, but then we're given Y, and so we invent all sorts of eloquent reasons why Y is actually a much better alternative and how we wanted Y all along. (What sort of fool would choose X?)
Lars Hall and Peter Johansson explain:
For example, in an early study we showed our volunteers pairs of pictures of faces and asked them to choose the most attractive. In some trials, immediately after they made their choice, we asked people to explain the reasons behind their choices.Unknown to them, we sometimes used a double-card magic trick to covertly exchange one face for the other so they ended up with the face they did not choose. Common sense dictates that all of us would notice such a big change in the outcome of a choice. But the result showed that in 75 per cent of the trials our participants were blind to the mismatch, even offering "reasons" for their "choice".
Importantly, the effects of choice blindness go beyond snap judgements. Depending on what our volunteers say in response to the mismatched outcomes of choices (whether they give short or long explanations, give numerical rating or labelling, and so on) we found this interaction could change their future preferences to the extent that they come to prefer the previously rejected alternative. This gives us a rare glimpse into the complicated dynamics of self-feedback ("I chose this, I publicly said so, therefore I must like it"), which we suspect lies behind the formation of many everyday preferences.
This reminds me of the influential work done by Roger Sperry and Michael Gazzaniga on split-brain patients, who have had their two hemispheres disconnected. The scientists mischievously flashed different sets of pictures to each eye, which meant each hemisphere was getting a different set of inputs. For example, they would flash a picture of a chicken claw to the right eye and a picture of a snowy driveway to the left eye. The patient was then shown a variety of images and asked to pick out the image that was most closely associated with what they had seen. In a tragicomic display of indecisiveness, the split-brain patient's two different hands pointed to two different objects. The right hand pointed to a chicken (this matched the chicken claw that the left hemisphere witnessed), while the left hand pointed to a shovel (the right hemisphere wanted to shovel the snow.) When the scientists asked the patient to explain his contradictory responses, he immediately generated a plausible story. "Oh, that's easy," he said. "The chicken claw goes with the chicken, and you need a shovel to clean out the chicken shed." Instead of admitting that his brain was hopelessly confused, he wove his confusion into a neat explanation.
Gazzaniga blamed this behavior on "the interpreter" module, located somewhere in the left hemisphere. The basic idea is that the brain is constantly trying to weave a narrative out of the cacophony of reality - it's desperate to make sense of the world. Interestingly, much of this narrative is written in reverse, as we brazenly re-write what just happened. We conveniently forget that we didn't choose that attractive face, or that the shovel has nothing to do with the chicken shed. The ridiculous contradiction isn't suppressed - it's not even noticed. We end up happily justifying choices we didn't make.
Why do we do this? I like to think of these confabulations as necessary half-truths to preserve the unity of the self. At any given moment, our mind is overstuffed with disparate sensations and fleeting thoughts; our different hemispheres want different things and distinct blobs of brain pump out distinct emotions. Why, then, do we feel like a unified person? Why do I feel like "Jonah" and not like a collection of random and stray neural emanations? Because we tell ourselves a story. Just as a novelist creates a narrative, we create a sense of being. The self, in this sense, is our work of art, a fiction created by the mind in order to make sense of its own fragments. In Proust Was A Neuroscientist, I quote Virginia Woolf on this mental process:
Am I here, or am I there? Or is the true self neither this nor that but something so varied and wandering that it is only when we give rein to its wishes and let it take its way unimpeded that we are indeed ourselves?
Brain & Behavior
Comments (154)
"Just as a novelist creates a narrative, we create a sense of being. The self, in this sense, is our work of art, a fiction created by the mind in order to make sense of its own fragments."
I love the idea of our Self as a narrative. It makes sense of so much disparate data (I think there's some recursion here!).
Cf. also the work of Bhattacharya and Sheth on insight.
I'd also like to hear your perspective on Libet's work. I don't recall your mentioning him in How We Decide (and I have not read Proust).
Posted by: dbuddah | April 25, 2009 10:27 AM