What are we reading? The emotional trend in 20th century books

cats are reading a book

cats are reading a book (Photo credit: Catunes)

Now there have been trends and there are new ones emerging with the release of every new Bestseller Lists. So, in this huge dynamics of book genre trends, it is worthwhile to know –

Which moods, or emotions, have been popular in the literature of the 20th century? 

Do the various world events happening around us affect our book choices too?

Are the claims that  Twitter mood words can predict stock market trends true ?

Can we glean at our past and see whether our mood patterns have reflected world changes?

Recently, an interesting piece of research came to answer these questions of mine. PLoS One an open access, peer reviewed journal published a research paper  by Alberto Acerbi and other co-researchers  titled – The Expression of Emotions in 20th Century BooksAs i said earlier their aim was to understand

To find out, researchers created six categories of words to express anger, disgust, fear, joy, sadness and surprise.

To do this they use Google’s excellent Ngram viewer, a phrase-usage graphing tool which charts the yearly count of selected n-grams (letter combinations)[n] or words and phrases,as found in over 5.2 million books digitized by Google Inc (up to 2008). Using this, the researchers looked at all English language literature published between 1900 & 2000.Apart from this, they used additional datasets for analysing mood words used in English fiction.

Figure 1. Historical periods of positive and negative moods.

So, lets look at the results starting from the above figure. It shows that moods tracked broad historical trends, including a ‘sad’ peak corresponding to Second World War, and two ‘happy’ peaks, one in the 1920’s and the other in the 1960’s. In more recent years we can see a ‘sad’ period starting from the 1970’s, with an increase in ‘happiness’ in the last years of the data set. Interestingly, the First World War does not seem to register a particular change in mood words.

Figure 2. Decrease in the use of emotion-related words through time.


The second part of results is shown in the above figure. It indicates that the usage of the mood words have decreased in books published in the 20th century. One thing which is indeed highly curious is that the use of words relating to disgust has declined the most. Another strange trend is that the use of fear-related words decreased until the 1970s, when the trend took a sharp turn upwards (and has continued to climb for the next three decades).

For me, it is indeed quite a surprise since it gives a fresh perspective on the last century. However, this sort of detailed use of word data to characterize the evolution of cultural differences and trends, to detect patterns previously unknown through conventional history is quite an exciting way to look into human cultural dynamics.

So, Yay for more such research !!


More to read about:

1). Acerbi A, Enquist M, Ghirlanda S (2009) Cultural evolution and individual development of of openness and conservatism. Proceedings of the National Academy of Sciences USA 106(45): 18931–18935.

2). Nettle D (2007) Language and genes: A new perspective on the origins of human cultural diversity. Proceedings of the National Academy of Sciences USA 104: 10755–10756.

3). Evans N, Levinson SC (2009) The myth of language universals: Language diversity and its importance for cognitive science. Behavioral and Brain Sciences 32: 429–492.

4). Bollen J, Mao H, Zeng X-J (2011) Twitter mood predicts the stock market. Journal of Computational Science 2: 1–8.


Research suggests, Facebook chats are more memorable than books !!

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Online social networking is highly popular and allows its members to post their thoughts as micro-blogs. This opportunity is exploited by people on Facebook alone, over 30 million times an hour. One does think that such trivial ephemera, would vanish quickly from everyone’s memory. However, they may comprise the sort of information that our memories are tuned to recognize, if that which we readily generate, we also readily store. Recent research published in the journal Memory & Cognition by cognitive psychologist Laura Mickes of the University of California, San Diego, and her colleagues, suggests that Facebook posts are one-and-a-half times as memorable as book sentences.

How they did it?

The authors initially were not researching on Facebook chats per se, but were looking into the effects of emotions on memory, and they happened to be using Facebook posts to invoke various feelings. What they surprisingly found was that the status updates seemed to be memorable all on their own.  They gathered Facebook posts from the accounts of undergraduate research assistants and also randomly selected sentences from recently published books.  They then stripped the posts and book excerpts of their context, and then asked a few college undergraduate students  to study and memorize the selected phrases from either Facebook or books, assigning equal number of students to each group. Then they sat the volunteers in front of a computer screen and, one at a time, displayed either a sentence the volunteer had studied or a sentence that was new to the volunteer. The team asked the subjects if they had seen each before, and how sure they were about it.

What does it prove?

All of this points out to the fact that Facebook, Twitter and other such social messaging platforms have brought the fluidity of personal conversations into written text. And we all know how easily we remember social conversations better.

All of this however, does not mean that you can cram for exams by posting chitchats on Facebook, Twitter etc!!