The English historian Edward Gibbon attributed the decline and fall of the once ubiquitous Roman Empire to the gradual, enervating loss of martial dedication and civic discipline among its citizenry. In a way, the Romans did not keep up the appearances required of an enduring civilization. Put simply, the slipping of standards led to the sinking of an empire.
One could argue much the same about the rise and fall of another once ubiquitous phenomenon of Western civilization, namely, hat wearing. A number of speculative theories have been posited attempting to explain the decline of hat wearing ranging from the rise of automobiles to the social fissures created in the 1960s by the Vietnam War and the baby boomer generation. The author of Hatless Jackaddresses the popular notion that a young, dynamic and hatless JFK hammered in the final nail in the coffin of hat wearing. These are certainly plausible explanations but they all suffer from a severe lack of data, evidence and supporting material.
This article attempts to fill this evidentiary gap and may be the first application of "culturomics" (i.e. computational analysis of digitized texts) to menswear or fashion generally speaking. N-grams are sequences of text or speech, which, when combined with Google's digitization of millions of books between 1500 and 2008, provide a unique historical record over 500 years of human history across several different languages.
When the Google Ngram Viewer was released in 2010, the first n-gram analyses I generated were for my book, currently in progress, combining a practical guide and intellectual history of men's style (which I will likely split into two separate works).
I think the Ngram Viewer offers some very suggestive insights on the gradual but almost complete collapse of hat wearing. Analysis of n-grams are unlikely to establish causality in the scientific sense but it can help make sense of why something happened and the social and cultural context around the specific practice and concept behind the n-gram. In this case, I'm proposing to analyze the word "hat" as a means to explore, starting with the linguistic record, linkages to the social practice of hat wearing.
Hypothesis #1: Hat wearing can be correlated to specific historical periods.
I interpret the n-gram plot below to indicate three phases - bubble or boom years (1860-1900), a "golden age" (1900-1940) and a "golden decline" of hats (1940-1960). These correlate respectively to the Victorian-Edwardian era, World War I/Roaring Twenties and postwar US and Europe.
The question then becomes a matter of building a plausible theory of the social, cultural and economic drivers in each period which can explain why the word-stock of hats grew, peaked and declined in the three eras identified above.
Hypothesis #2: The decline of hat wearing may be correlated with the decline of the social concept and practice of being a gentleman.
At first blush, there doesn't appear to be any correlation between "hat" and "gentleman" in the n-gram plot below. But it is interesting to note the peaks and valleys in the usage of "gentleman" circa 1800-1820 and 1900-1920, suggesting again underlying linkages to historical events during those time periods. The fact that the word hat persists at a consistent rate over 200 years is also noteworthy, at least compared to the steady and absolute decline of gentleman in the digitized corpus.
Hypothesis #3: Events in popular culture reported by mass media can influence linguistic usage and the actual practice of hat wearing.
Below we see an interesting fluctuation in the frequency of texts mentioning Stetson hats. I surmise the peaks are generated by specific films, tv shows, celebrities or other events covered by media outlets during those time periods.
In order to make progress on this hypothesis, the n-gram analysis above needs to be augmented with actual hat production numbers.