Emotional expression in Anglophone fiction declines over two centures

Oliver Morin and Alberto Acerbi, Birth of the cool: a two-centuries decline in emotional expression in Anglophone fiction, Cognition and Emotion, Volume 31, 2017 - Issue 8, https://doi.org/10.1080/02699931.2016.1260528.

Abstract: The presence of emotional words and content in stories has been shown to enhance a story’s memorability, and its cultural success. Yet, recent cultural trends run in the opposite direction. Using the Google Books corpus, coupled with two metadata-rich corpora of Anglophone fiction books, we show a decrease in emotionality in English-speaking literature starting plausibly in the nineteenth century. We show that this decrease cannot be explained by changes unrelated to emotionality (such as demographic dynamics concerning age or gender balance, changes in vocabulary richness, or changes in the prevalence of literary genres), and that, in our three corpora, the decrease is driven almost entirely by a decline in the proportion of positive emotion-related words, while the frequency of negative emotion-related words shows little if any decline. Consistently with previous studies, we also find a link between ageing and negative emotionality at the individual level.

From the introduction:

In this paper, we attempt to provide a better grounding for the hypothesis that the decreasing in emotion-related words is a real linguistic and cultural phenomenon, and to contextualise it in a wider cognitive and cultural framework. First, we ran a new analysis on the Google Books corpus, focusing on the English Fiction sample from the second version (2012) of the corpus, in which the influx of the increase of technical literature seems to be absent or strongly limited (Pechenick et al., 2015). Second, we replicated this analysis on two “small data” corpora: collections of books that we built ourselves, and for which we have all the relevant metadata needed to control for a variety of factors (the author’s age, gender, and vocabulary size, to cite the most important).

We report four main findings. (i) Our data confirm that the decrease in emotionality in English-speaking literature is no artifact of the Google Books corpus, and that it pre-dates the twentieth century, plausibly beginning in the early nineteenth century; (ii) this general decline cannot be explained by changes unrelated to emotionality (such as demographic dynamics concerning age or gender balance, changes in vocabulary richness, or changes in the prevalence of literary genres); (iii) in our three corpora, this decrease in the proportion of emotion-related words in literary texts is driven almost entirely by a decline in the proportion of positive emotion-related words, while the frequency of negative emotion-related words shows little decline (if any), and (iv) author’s age, consistently with previous studies (Pennebaker & Stone, 2003), covaries with negative emotionality, with older authors using proportionally fewer negative emotion-related words.

In the discussion, we consider several possible explanations for the birth of a “cool”, detached emotional style that avoids positive emotional expression. A dynamic of “regression to the mean” following the domination, in the late eighteenth and early nineteenth century, of the exuberant Romantic style, is one possibility. Overall, we take our work as showing the importance of the combined use of “big data” (abundant, but lacking in metadata, datasets) and “small” data (datasets more restricted, but metadata-rich) to investigate cultural changes. In addition, our results suggest that the “Pollyanna effect” (the predominance of positively valenced words over negatively valenced ones – (Boucher & Osgood, 1969; Kloumann, Danforth, Harris, Bliss, & Dodds, 2012) may not be an invariant feature of language, but is subject to historical fluctuations.