• Explain common roadblocks to problem-solving
• Explain choice blindness

But is it Real? The Value of Replication

The research you read about choice blindness conducted by Petter Johannson and Lars Hall had a surprising result: more than 75% of the time, people make a choice and then, without indicating that anything is amiss, they proceed to justify a choice they did not make. But how solid is this study and how much can we believe these results? Maybe the choice blindness experiment reported real results, but (even assuming that the experimenters were completely honest and careful) could this have just been a weird outcome that will never happen again? In other words, is this a reliable result or just a fluke?

There is only one way to determine if a phenomenon is reliable, and that is through replication. If you can’t replicate an effect, then you shouldn’t waste people’s time reading about it in a scientific paper.There are at least three different types of replication.

1. Direct Replication: Conduct exactly the same study again, usually with new participants from the same population as the original study. A successful replication would produce results similar to those in the original study.
2. Systematic Replication: Conduct a study that is similar to the original one, but using slightly different methods or stimuli.
3. Conceptual Replication: Conduct a very different study that still tests the original idea. In the current context, a conceptual replication would test the choice blindness idea using a method that did not involve choosing attractive people.

So, can you believe the choice blindness phenomenon? Let’s look at a few replications.

Case #1

In the years just before they published their 2005 study, the experimenters conducted two similar studies. For these studies, the pictures were presented on a computer screen, and the computer switched the pictures during the critical trials. The results were very similar to the results of the study where participants chose the attractive person.

Case #2

When the BBC (British Broadcasting Corporation) made the video you watched, they reconstructed the experiment in a form very similar to the original. They reported that 80% of the participants did not notice any switching of pictures—a result very similar to the original. Unfortunately, without a published report of the study, it is impossible to know if the scientific standards of the original study had been maintained.

Case #3

In 2014, researchers at the National University of Singapore reported a study similar to the experiment shown in the video. The stimuli were presented using a computer rather than a live experimenter. In addition to choosing one of the two faces, the participants rated their confidence in their choice and they typed their explanation of their preference. The faces were all of White women (as in the original study), but the participants were all of Asian descent (ethnic backgrounds: Chinese, Indian, and Vietnamese). Their results were similar to those of the original study.

Case #4

Here is video showing another study by Johannson and Hall. The video has no sound—only subtitles.

Before an election, researchers polled people about their political preferences, selecting either right-wing or left-wing policies. The researchers secretly copied down the opposite of their responses and had the participants explain their answers. Fascinatingly, many people defended the views they said to have disagreed with.
You can view the transcript for “Using Choice Blindness to Shift Political Attitudes and Voter Intentions” here (opens in new window).