In today’s Outside the Box, Robert Epstein, a senior research psychologist at the American Institute for Behavioral Research and Technology in California and the former editor-in-chief of Psychology Today, warns us of a insidious and pervasive new form of mind control: search results.

That’s right, search results. And not just any search results: Google search results. Since 2013 Epstein and colleagues have conducted a number of experiments in the US and India to determine whether search results can impact people’s politicalopinions.

Epstein points out that about 50 percent of our clicks go to the top two items on the first page of results, and more than 90 percent of our clicks go to the 10 items listed. And of course Google, which dominates the search business, decides which of the billions of web pages to include in our search results, and it decides how to rank them.

But surely, Epstein thought, a top search result would have only a small impact on a person’s political choices. Not so! To Epstein’s surprise, in his initial experiment he found that theproportion of people favouring the (bogus, skewed) search engine’s top-ranked candidate increased by more than 48 percent! Also, 75 percent of the subjects in the study were completely unaware that they were viewing biased search rankings.

He conducted several more experiments, including one that involved more than 2,000 people from all 50 US states. In that experiment, the shift in voting preferences induced by the researchers was 37 percent, and as high as 80 percent in some demographic groups.

Epstein was still skeptical. He asked,

Could voting preferences be shifted with real voters in the middle of a real campaign? … In real elections, people are bombarded with multiple sources of information, and they also know a lot about the candidates. It seemed unlikely that a single experience on a search engine would have much impact on their voting preferences.