Bogus Pipeline, Bona Fide Pipeline

byScott Alexander10y24th Mar 200916 comments


Related to: Never Leave Your Room

Perhaps you are a psychologist, and you wish to do a study on racism. Maybe you want to know whether racists drink more coffee than non-racists. Sounds easy. Find a group of people and ask them how racist they are, then ask them how much coffee they drink.

Problem: everyone in your study says they're completely non-racist and some of their best friends are black and all races are equally part of this vast multicolored tapestry we call humanity. Maybe some of them are stretching the truth here a bit. Until you figure out which ones, you're never going to find out anything interesting about coffee.

So you build a foreboding looking machine out of gleaming steel, covered with wires and blinking lights. You sit your subjects down in front of the machine, connect them to its electrodes, and say as convincingly as possible that it is a lie detector and they must speak the truth. Your subjects look doubtful. Didn't they hear on TV that lie detectors don't really work? They'll stick to their vehement assertions of tolerance until you get a more impressive-looking machine, thank you.

You get smarter. Before your experiment, you make the subjects fill in a survey, which you secretly copy while they're not looking. Then you bring them in front of the gleaming metal lie detector, and dare them to try to thwart it. Every time they give an answer different from the one on the survey, you frown and tell them that the machine has detected their fabrication. When the subject is suitably impressed, you start asking them about racism.

The subjects start grudgingly admitting they have some racist attitudes. You have invented the Bogus Pipeline.

The Bogus Pipeline is quite powerful. Since its invention in the 70s, several different studies demonstrate that its victims will give significantly less self-enhancing answers to a wide variety of questions than will subjects not connected to the machinery. In cases where facts can be checked, Pipeline subjects' answers tend to be more factually correct than normal subjects'.

In one of the more interesting Bogus Pipeline experiments, Millham and Kellogg wanted to know how much of a person's average self-enhancement is due to self-deception biases, and how much is due to simple lying. They asked people some questions about themselves under normal and Pipeline conditions, using the Marlowe-Crowne scale. This scale really deserves a post of its own, but the short version is that it asks you some loaded questions, and if you take them as an opportunity to say nice things about yourself, you get marked down as a self-enhancer. There was a correlation of .68 between Marlowe-Crowne scores in normal and Pipeline conditions. If we accept that no one deliberately lies under the Pipeline, that means we now know how much self-enhancement is, on average, self-deception rather than deliberate falsehood (tendency towards deliberate falsehoods correlated .37 with Marlowe-Crowne.1)

Interesting stuff. But you still don't know whether racists drink more coffee! Your Bogus Pipeline only eliminates part of the self-enhancement in your subjects' answers. If you want to solve the coffee question once and for all, you can't count on a fake mind-reading device. You need a real mind-reading device. And in the mid 90s, psychology finally developed one.

The Bona Fide Pipeline is far less impressive-looking than the Bogus Pipeline. Though the Bogus Pipeline tries as hard as it can to scream "mind-reading device", the Bona Fide Pipeline has a vested interest in preventing its victims from realizing their minds are being read. It is a simple computer terminal.

The Pipeline uses a complicated process to disguise itself as an ordinary study on distraction or face recognition or somesuch, but the active ingredient is this: the subjects play a game where they must hit one key (perhaps "A") if the screen displays a good word (for example "wonderful"), and a different key (perhaps "L") if the screen displays a bad word (for example "ugly").

But before it gives you the word, it shows you a picture of a white person or a black person. Remember priming? That picture of a black person is going to prime your brain's concept of "black person" and any concepts you associate with "black person". If you have racist attitudes, "bad" is one concept you associate with "black person". You're going to have a very easy time recognizing "ugly" as a bad word, because your "bad" concept is already activated. But you're going to have a harder time recognizing "wonderful" as a good concept, because your brain is already skewed in the opposite direction. It's not impossible, it's just going to take a few hundred more milliseconds. Each of which the Bona Fide Pipeline is recording and processing. At the end, it spits out a score telling you that you took an average of three hundred milliseconds longer to recognize good words when primed with black people's pictures than white people's pictures.

Does this actually work? The original study (Fazio et al, 1995) tested both whites and blacks, and found the whites were more likely to be prejudiced against blacks than the blacks were, which makes sense. In the same study, a black experimenter conversed with the subjects for a while, and rated the quality of the interaction by a typically rigorous rubric. This fuzzy unscientific measure of racist behavior correlated well with the Pipeline's data for the individuals involved. A study by Jackson (1997) find that people who score high on prejudice by Pipeline measures on average give lower scores to an essay written by a student known to be black.

The Bona Fide Pipeline has lately been superseded by its younger, sexier, Harvard-educated cousin, the IAT. More on that, the associated controversy, and the relevance to rationality tomorrow.


1: I doubt that deceptions can be separated cleanly into self-deception and deliberate falsehood like this. More likely there are many different shades of grey, and the Bogus Pipeline captures some but not all of them.