A remarkable paper just published in PLoS ONE reports on what is, I think, one of the largest psychological experiments of all time. Researchers Elizabeth L. Paluck and colleagues partnered with a TV network to insert certain themes (or messages) into popular dramas shown on US TV. They then looked to see whether these themes had an effect on real world behavior, ranging from Google searches to drink-driving arrests. The study was based on three prime time Spanish-language dramas (telenovelas) which have a viewership of around 1.2 million people per week. Telenovelas are a genre similar to English-language soap operas except shorter, most lasting about a year. Into these shows, eight messages were added, ranging from health and safety (benefits of low cholesterol, dangers of drink driving) to community building (register to vote, scholarships for Hispanic students.) In total, there were 23 scenes, featuring 16 minutes and 51 seconds of footage. The scenes were "not central to the shows’ plots" but "many involved the shows’ main characters." What makes this a genuine experiment (rather than just an observational study) is that the researchers used randomization to determine when in the season to broadcast each message. So did it work? Not really. The airing of scenes featuring the Hispanic Scholarship Fund did lead to large (but temporary) spikes in the number of people visiting that organization's website.