Searching for information online may boost how much you think you know, but it’s just an illusion.

That’s the findings of researchers at Yale who’ve published their work through the American Psychological Association.

A team led by Matthew Fisher carried out nine experiments, each involving half of participants being asked to search online to research four questions and find the page they thought best answered the questions. The other half of participants were then asked to read a printout of the page that got the most ‘votes’ from the online searchers.

Across the experiments, the researchers then used different methods of assessing the participants perception of their own knowledge. In one experiment the participants were presented with fresh questions on topics unrelated to those used in the initial section and asked to rate their own ability to answer the question. Those who’d carried out the online search ‘consistently’ rated their own abilities higher than did those who’d only read the printouts.

In another experiment each participant was shown a collection of MRI scan of their brains and asked which they thought most represented their own. Those who’d searched online were more likely to pick those scans which showed more active areas.

In another variant, the Internet group was not asked to search for an answer but were simply given a link to a page that would answer the question. In this situation, the self-perceived level of knowledge was no different from those given a printout.

And in yet another variant, the researchers made sure the Internet group would not be able to find a satisfactory answer: in some cases because the question topic was so complex that it couldn’t be answered in a simple search, and in others because the researchers had filtered the search engines to block relevant pages. Despite this, the Internet group still felt more knowledgeable than the control group.

The researchers believe the findings show that it’s not the act of accessing information on-screen rather than on paper that changes people’s self-belief. Instead, the act of searching for answers online makes people feel more knowledgeable and this perception lasts beyond the point at which they stop searching.

They say that given the growing ease of searching online offered by smartphones, there’s a risk that people may increasingly overestimate and rely on their own knowledge.