Researchers showed the effects of âmass psychological persuasionâ using Facebook Credit: Reuters
Researchers used âmass psychological persuasionâÂ in an online ad campaign that saw sales rise by more than 50 percent.Â
In an experiment that targeted 3.5 million people, the academics used just a single Facebook "like" for each user to glean a psychological trait - whether they were introverted or extroverted.Â
This characteristic was then used to tailor anÂ ad for each consumer in an effort to influence them.Â
Clicks on targeted ads for beauty products and games apps rose by up to 40 percent while sales increased by more thanÂ 50 percent compared with adverts that had not been customised.Â
Researchers, who did not benefit financially from the campaigns, noted the extent to which just a tiny portion of a consumer's digital footprint could be used to influence their actions.Â
"Our findings represent a conservative estimate of the potential effectiveness of psychological mass persuasion in the field," the authors report in the US journal Proceedings of the National Academy of Sciences.
Carried out for unnamed companies, the study highlighted the potential benefits ofÂ psychological targeting, but also underscored the risk that it could be used to exploit vulnerable individuals.
Targeting ads forÂ self-help literature or counselling services to highly neurotic individuals who display early signs of depression could have a positive effect, the authors wrote.
But they also warned the same techniques could be used toÂ target online casino advertisements at individuals who are susceptibleÂ to pathological gambling.Â
The study also noted unconfirmed reports thatÂ psychological persuasion was used in the US election to deter people from voting.Â
"It illustrates clearly how psychological mass persuasion could be abused to manipulate people to behave in ways that are neither in their best interest nor in the best interest of society," the authors wrote.Â
To carry out the study, researchers in the US worked with academics at the University of Cambridge who had built a database of the "likes" of millions of anonymous Facebook users.
The information suggested a "like" on Lady Gagaâs Facebook page was indicative of an extrovert, while a like on Stargateâs page suggested a more introvert personality.Â Adverts were then designed to appeal to the different groups.
The first experiment, for an online beauty retailer and aimed at UK women aged 18-40, reached more than 3.1 million people.
The campaign resulted in 360 sales as more than 10,000 people clicked on the ads. Customising the ads to specific personality types saw 54 percent more purchases than advertising that was not targeted.Â
A further two experiments, forÂ a crossword app andÂ a bubble shooter game, reached fewer people but had similar results.Â
Sandra Matz, one of the study's authors, told the GuardianÂ they wanted to show clearly how the behaviour of internet usersÂ could be influenced using their digital footprint.Â
âWe wanted to provide some scientific evidence that psychological targeting works, to show policymakers that it works, to show people on the street that it works, and say this is what we can do simply by looking at your Facebook likes.â