I always wondered why old movies are rated so high on IMDb.
For example, 12 Angry Men (1954) with just ~900K votes ranks about as high as Inception (2010) with ~2M votes. Few people I know have seen 12 Angry Men. So where does this high rating come from?
My theories were:
- Old movies really are that good.
- IMDb’s algorithm is biased towards old movies.
- People remember older movies fondly.
Actually, it’s none of these. It’s selection bias.
Few people watch a 1950s black & white drama: cinephiles, film students, etc. They love it and give it 9s and 10s.
Everyone watched Inception. The casual majority thinks it’s fine, not life changing. Maybe a 7 or 8.
This creates a paradox: obscurity protects ratings while popularity is its own punishment. Only “devotees” watch obscure movies - leading to better ratings than widely seen movies.
PS: This data analysis and story were authored by Claude Code. That includes the statistical significance validation.
Story: https://sanand0.github.io/datastories/imdb-democracy-penalty/index.html Prompt: http://github.com/sanand0/datastories/tree/main/imdb-democracy-penalty Code: https://github.com/sanand0/imdbscrape/pull/1
