Wednesday, 23 July 2014

What the textbooks don't tell you - one of psychology's most famous experiments was seriously flawed

Zimbardo speaking in '09
Conducted in 1971, the Stanford Prison Experiment (SPE) has acquired a mythical status and provided the inspiration for at least two feature-length films. You'll recall that several university students allocated to the role of jailor turned brutal and the study had to be aborted prematurely. Philip Zimbardo, the experiment's lead investigator, says the lesson from the research is that in certain situations, good people readily turn bad. "If you put good apples into a bad situation, you’ll get bad apples," he has written.

The SPE was criticised back in the 70s, but that criticism has noticeably escalated and widened in recent years. New details to emerge show that Zimbardo played a key role in encouraging his "guards" to behave in tyrannical fashion. Critics have pointed out that only one third of guards behaved sadistically (this argues against the overwhelming power of the situation). Question marks have also been raised about the self-selection of particular personality types into the study. Moreover, in 2002, the social psychologists Steve Reicher and Alex Haslam conducted the BBC Prison Study to test the conventional interpretation of the SPE. The researchers deliberately avoided directing their participants as Zimbardo had his, and this time it was the prisoners who initially formed a strong group identity and overthrew the guards.

Given that the SPE has been used to explain modern-day atrocities, such as at Abu Ghraib, and given that nearly two million students are enrolled in introductory psychology courses in the US, Richard Griggs, professor emeritus at the University of Florida, says "it is especially important that coverage of it in our texts be accurate."

So, have the important criticisms and reinterpretations of the SPE been documented by key introductory psychology textbooks? Griggs analysed the content of 13 leading US introductory psychology textbooks, all of which have been revised in recent years, including:  Discovering Psychology (Cacioppo and Freberg, 2012); Psychological Science (Gazzaniga et al, 2012); and Psychology (Schacter et al, 2011).

Of the 13 analysed texts, 11 dealt with the Stanford Prison Experiment, providing between one to seven paragraphs of coverage. Nine included photographic support for the coverage. Five provided no criticism of the SPE at all. The other six provided only cursory criticism, mostly focused on the questionable ethics of the study. Only two texts mentioned the BBC Prison Study. Only one text provided a formal scholarly reference to a critique of the SPE.

Why do the principal psychology introductory textbooks, at least in the US, largely ignore the wide range of important criticisms of the SPE? Griggs didn't approach the authors of the texts so he can't know for sure. He thinks it unlikely that ignorance is the answer. Perhaps the authors are persuaded by Zimbardo's answers to his critics, says Griggs, but even so, surely the criticisms should be mentioned and referenced. Another possibility is that textbook authors are under pressure to shorten their texts, but surely they are also under pressure to keep them up-to-date.

It would be interesting to compare coverage of the SPE in European introductory texts. Certainly there are contemporary books by British psychologists that do provide more in-depth critical coverage of the SPE.

Griggs' advice for textbook authors is to position coverage of the SPE in the research methods chapter (instead of under social psychology), and to use the experiment's flaws as a way to introduce students to key issues such as ecological validity, ethics, demand characteristics and subsequent conflicting results. "In sum," he writes, "the SPE and its criticisms comprise a solid thread to weave numerous research concepts together into a good 'story' that would not only enhance student learning but also lead students to engage in critical thinking about the research process and all of the possible pitfalls along the way."


Griggs, R. (2014). Coverage of the Stanford Prison Experiment in Introductory Psychology Textbooks Teaching of Psychology, 41 (3), 195-203 DOI: 10.1177/0098628314537968

--further reading--
Foundations of sand? The lure of academic myths and their place in classic psychology
Tyranny and The Tyrant,  From Stanford to Abu Ghraib (pdf; Phil Banyard reviews Zimbardo's book The Lucifer Effect).

Image credit: Jdec/Wikipedia
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.


Research Digest said...

Sutton and Douglas (2013) provide an in-depth critique of the SPE (pp. 400-404) in their introductory social psychology text book.

Research Digest said...

The very same about the "Little Albert" experiment. Not only wrong ethically, but experimentally flawed on all levels. Many textbooks still mention this experiment as if it were valid (as a model of phobia formation, usually), some even call it a "fact"... If you're looking for a deep reason why criticisim of widely-held mythical stories isn't mentioned in the Scriptures of Psychology (or elsewhere), look no further. People like stories more than they like science.

Research Digest said...

If you do an experiment so unethical it can never be replicated, you can make sure no one is ever able to formally disprove your results.

Research Digest said...

But how big is the effect and what fraction of the sample was subject to it not just does it exist. There's a difference between statistical significance and practical significance.

Research Digest said...

Repeat the experiment. It's for science. A couple of people suffer, humanity advances. That's how it works. Hop to it!

Research Digest said...

"Gaze avoidant women were also viewed by others in a negative light (as being disagreeable, unconscientious, unattractive, and even somewhat lower on intelligence). In males, none of the social judgment variables correlated significantly with gaze avoidance."

Research Digest said...

I've added a caveat in the relevant place.

Research Digest said...

Griggs paper sounds good. Never underestimate demand characteristics. But hey it's experimental psych. It's a mess. I was surprised there were that many psych texts. How could we possibly need them all? Also reminded of Stephen J. Gould's essay on the Cloning Fox Terrier. Textbook writers often copy examples from earlier ones.

Research Digest said...

Hmmm .... interesting enough I relate to most of the topics. It is impressive that the human mind can make a judgement on someone within one tenth of a second! But I do it all the time. I would agree to most of the categories that people have perspectives lined out for us. in our society when imagining a sales clerk, the picture is not a long haired, loose fitting clothes gentleman that speaks slowly, we expect a quick speaking well dressed clerk to sell me that dishwasher I know nothing about! Intelligence is judged in a similar fashion. Society or life experiences have taught us who to trust and who is more likely to be more intelligent. I do believe there are exceptions to every rule, just because you enjoy expressing yourself with tattoos or piercing does not make you dumb! The other choices one makes determines that outcome. Classic conditioning plays a large role in decisions and outcomes of our adult life.

Research Digest said...

"People who have multiple facial piercings are assumed to be less intelligent" - Isn't that because they are? Anyone who intentionally puts shrapnel in their face must be lacking in something.... not Iron, but something. The tattoo craze at the moment worries me, there will be a lot of people unhappy with their bodies once its popularity makes it unfashionable.

Research Digest said...

This is so ignorant. I have a beautiful full sleeve and am on my way to earning a Ph.D. I am currently working as a scientist and in the near future, I will also be a professor. My tattoos are not some ugly drawings picked out of a book, they are works of art drawn by an artist. I would never get something tattooed on me because "it looked cool." Not everyone with tattoos is stupid nor do we all just get the first thing we see to get it done. I put years of thought into my tattoos and I regret none of them.

Research Digest said...

You are so insecure.

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