What is The Rabbit Hole?
The 'Up Next' sidebar is designed to pull you away from what you originally searched for, often by recommending content that is more emotionally intense than what you are watching.
Where it comes from
YouTube Autoplay Era (2015)
How it hooks you
Exploits the curiosity gap: each recommended thumbnail promises something slightly more provocative than the current video.
What the research shows
In Mozilla's crowdsourced study, 71% of videos volunteers regretted watching were recommended to them by YouTube's algorithm.
How to resist it
Hide the recommendation sidebar with an extension like Unhook, and watch only what you came for.