Tuesday, 30 June 2015

What the textbooks don't tell you about psychology's most famous case study

Image: Photograph by Jack Wilgus of
a daguerreotype of Phineas Gage
in the collection of Jack and Beverly Wilgus.
It's a remarkable, mythical tale with lashings of gore – no wonder it's a favourite of psychology students the world over. I'm talking about Phineas Gage, the nineteenth century railway worker who somehow survived the passing of a three-foot long tamping iron through the front of his brain and out the top of his head. What happened to him next?

If you turn to many of the leading introductory psychology textbooks (American ones, at least), you'll find the wrong answer, or a misleading account. Richard Griggs, Emeritus Professor of Psychology at the University of Florida, has just analysed the content of 23 contemporary textbooks (either released or updated within the last couple of years), and he finds most of them contain distortions, omissions and inaccuracies.

It needn't be so. Thanks to painstaking historical analysis of primary sources (by Malcolm Macmillan and Matthew Lena) – much of it published between 2000 and 2010 – and the discovery during the same time period of new photographic evidence of post-accident Gage (see image, right), it is now believed that Gage made a remarkable recovery from his terrible injuries. He ultimately emigrated to Chile where he worked as a horse-coach driver, controlling six horses at once and dealing politely with non-English speaking passengers. The latest simulations of his injury help explain his rehabilitation – it's thought the iron rod passed through his left frontal lobe only, leaving his right lobe fully intact.

Image: From Van Horn et al 2012
Yet, the textbooks mostly tell a different story. Of the 21 that cover Gage, only 4 mention the years he worked in Chile. Only three detail his mental recovery. Fourteen of the books tell you about the first research that attempted to identify the extent of his brain injuries, but just four of the books give you the results from the most technically advanced effort, published in 2004, that first suggested his brain damage was limited to the left frontal lobe (watch video). Only 9 of the books feature either of the two photos to have emerged of Gage in recent times.

So the textbooks mostly won't tell you about Gage's rehabilitation, or provide you with the latest evidence on his injuries. Instead, you might hear how hear never worked again and became a vagrant, or that he became a circus freak for the rest of his life, showing off the holes in his head. "The most egregious error," says Griggs, "seems to be that Gage survived for 20 years with the tamping iron embedded in his head!".

Does any of this matter? Griggs argues strongly that it does. There are over one and half million students enrolled in introductory psychology courses in the US alone, and most of them are introduced to the subject via textbooks. We know from past work that psychology textbook coverage of other key cases and studies is also often distorted and inaccurate. Now we learn that psychology's most famous case study is also misrepresented, potentially giving a misleading, overly simplistic impression about the effects of Gage's brain damage. "It is important to the psychological teaching community to identify inaccuracies in our textbooks so that they can be corrected, and we as textbook authors and teachers do not continue to 'give away' false information about our discipline," Griggs concludes.

_________________________________ ResearchBlogging.org

Griggs, R. (2015). Coverage of the Phineas Gage Story in Introductory Psychology Textbooks: Was Gage No Longer Gage? Teaching of Psychology, 42 (3), 195-202 DOI: 10.1177/0098628315587614

--further reading--
Phineas Gage - Unravelling the Myth
Coverage of Phineas Gage in "Great Myths of the Brain"
Glimpsed at last - the life of neuropsychology's most important patient (Monsieur Leborgne)
Foundations of Sand - the lure of academic myths and their place in classic psychology.
Looking back: Blasts from the past

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

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