Here’s something odd I noticed in looking at the frequencies of various words published in books as reported by Google NGram viewer. Here is the consolidated graph of the frequences of eight related words:
The chaos on the left side of the graph reflects the small-number statistics of early printing; by 1700 there were enough books in Google’s sample to give more reliable results. You will note that the curves for the twentieth century are the smoothest of the lot; this reflects the large number of books published in that century. Also please note that I normalized these curves; that is, I presented them not on the true scale — all the scales are different — but instead on the same RELATIVE scale. This serves to show not how popular these words are, but rather how their popularity changed with time.
All of these words (despair, joy, pleasure, elated, happiness, amusement, and melancholy) represent emotional states. All of them show the same basic pattern: a sharp rise in relative frequencies starting around 1725, peaking around 1810, and then slowly declining until the year 2000, when they all show small upticks.
What’s going on here? My hunch is that English language books in the early 18th century were heavily biased towards theological topics, which would relegate words describing emotions to low frequencies. But in the second half of the 18th century we saw the beginnings of Romanticism.
What I find most interesting, however, is the uptick in the 21st century. Why are people suddenly more interested in emotional states? Does this represent a turning inward? A relaxation of the seriousness imposed upon English-speakers by the Cold War? The effect of video games? (Just kidding!)
Much food for thought here.