It’s not your imagination. Lyrics are getting sadder and angrier.

Live long enough and you’ll begin to notice shifts in culture that happen not over months but years or even decades. Such is the case with song lyrics.

A new scientific study of 6,150 songs from the Billboard Top 100 from the last 60 years (1951-2016) conducted at Lawrence Technological University in Southfield, Michigan, reveals that over time, songs have been getting sadder and angrier.

Given that the Hot 100 lists the most popular songs of a moment, it’s not a stretch to say they reflect the zeitgeist of society at the time they’re hot. Music is a great cultural barometer and the mood of our music is always downstream from what’s going on in the world.

Here’s an executive summary of the study (which, by the way, can be found here.)

1. Lyrics expressing fear and disgust have been on the rise
2. Songs that express joy, confidence, and openness have been on the decline.
3. The happiest songs (or at least the ones expressing the least anger) were dominant in the 1950s.
4. Anger was the emotion that increased the most, with disgust and fear coming next.
5. Bottom line? Music has become more negative over the decades.

(Via USA Today)