Revisiting the U.S. Navy Submarine Service Psychological Casualty Rate in World War II

• DOI: 10.1177/0095327X19845422
• Date: 01 October 2020
• Published date: 01 October 2020
• Author: S. P. MacKenzie
• Subject Matter: Articles

Article

Revisiting the U.S. Navy

Submarine Service

Psychological Casualty

Rate in World War II

S. P. MacKenzie

1

Abstract

Conclusions concerning how many World War II U.S. Navy submariners should be

classified as psychiatric casualties have long been based on a pioneering study by two

navy physicians, Commander Ivan Duff, MD, and Captain Charles Shilling, MD, that

was first made public in the Journal of the American Psychiatric Association shortly after

the war. This article seeks to show that, despite the longevity of the resulting

published figures, there were serious problems in their approach and conclusions.

The data set of the study was far from comprehensive, which, in turn, led to

erroneous calculations generating a minuscule number—approximately two cases

per 1,000 submariners—that in turn necessitated explanatory overreach. Reasons

for the approach taken in the original work, and subsequent longevity of acceptance

and celebration of the results produced, are then examined through the lens of

confirmation bias.

Keywords

methodology, cohesion/disintegration, command/control, discipline

1

Department of History, University of South Carolina, Columbia, SC, USA

Corresponding Author:

S. P. MacKenzie, Department of History, University of South Carolina, Gambrell Hall, Columbia,

SC 29208, USA.

Email: mackensp@mailbox.sc.edu

Armed Forces & Society

2020, Vol. 46(4) 735-753

ªThe Author(s) 2019

Article reuse guidelines:

sagepub.com/journals-permissions

DOI: 10.1177/0095327X19845422

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Over the past seven decades, the idea that under 60 American submariners, far less

than a 10th of a percent of those involved, could be counted as psychiatric casualties

during World War II has taken on the mantle of settled fact. The conclusions of an

internal study undertaken by two medical corps officers (Shilling & Kohl, 1947, pp.

117–128), subsequently published in the American Journal of Psychiatry (Duff &

Shilling, 1947, p. 612), have been periodically repeated more-or-less verbatim in

both official and nonservice publications (e.g., Chermol, 1985, p. 10) down into the

present century. The aim of this article is to demonstrate that American submariners

who found themselves psychologically unable to continue on war patrols must have

been greater in number than claimed and to explain through confirmation bias the

approach taken in the original study, the tendency to keep repeating its conclusions

down the years, and why this matters.

Determining Numbers

Engaged in an unrestricted campaign against Japanese shipping (see Holwitt, 2009),

those who served aboard American submarines during World War II faced a set of

physical and emotional challenges unique to subsurface operations. Quite apart from

living and working in a highly confined space on patrols that might last 7 weeks or

more, submariners had to contend with enemy efforts to kill them through depth

charging from surface vessels and bombing by anti-submarine aircraft. The physical

and emotional distress resulting from nearby underwater explosions and damage to a

boat from which there was little possibility of individual escape was amplified by the

necessity of silent running, in which machinery was shut off; conversation confined

to a whispered minimum; and temperature, humidity, and carbon dioxide levels

progressively rose. “There can be no doubt that the traumas experienced by the

personnel of the submarine service,” a p ostwar navy manual asserted, “were as

great, if not in excess, of that [sic] experienced by any other group in the war”; and,

as an inevitable consequence, “numbers of psychiatric casualties were encountered”

(Bureau of Medicine and Surgery, 1956, p. 307).

Just what these numbers were, however, remai ned unclear down through the

cessation of hostilities in the Pacific. At least some of the navy physicians examining

experienced submariners took mental s tatus into account (see, e.g., Amy, 1996,

p. 13; Mays, n.d.; Roberson, 1997, pp. 5–6) and were not shy about going on record

to get a man taken off combat duty due to the state of his nerves (e.g., J. Brown in

Jackson, 2010, p. 104; Whitlock & Smith, 2007, p. 275). “If there was some sort of

emotional problem,” noted one of the medical corps doctors stationed at the sub-

marine base on Midway Island,

we would transfer him off. Sometimes we got in trouble with the commanding officer

of the submarine if we took a man off that was a good man; but [if we] felt like he

shouldn’t be on the submarine, we’d have to do it. (Ramey, 2001)

736 Armed Forces & Society 46(4)