Short answers, pulled from the story.
The concept of a video going viral existed long before the internet with Reefer Madness circulating as an educational film in 1936. Keith Stroup distributed prints of this film at college film festivals during the 1970s to promote NORML.
YouTube launched in 2005 and was acquired by Google in 2006. Before YouTube, content circulated on sites like Newgrounds, YTMND, eBaum's World, and Something Awful.
Stanford University psychologist Albert Bandura introduced Social Learning Theory in 1977 proposing that people learn by observing others perceived as influential or similar to themselves. They then imitate observed behaviors especially when those behaviors lead to rewards like attention or approval through vicarious reinforcement.
A 2024 narrative review identified several TikTok trends resulting in injuries including the Rubbing Castor Oil Trend, Bleach Eye Challenge, Mucus Fishing Challenge, Orbeez Challenge, Sun Gazing Challenge, Stye Popping Challenge, Blow-Drying Eyelashes Trend, and Beezin trend. These activities risked infection, irritation, eye trauma, solar retinopathy, scarring, dermatitis, and conjunctivitis.
The 2008 United States presidential election showcased impact of political viral videos for the first time with YouTube hosting CNN-YouTube presidential debates calling on users to pose questions directly. Every major party candidate maintained their own YouTube channel during the campaign with John McCain posting over 300 videos and Barack Obama posting over 1,800 videos.