As much as the Internet might dominate our lives today, it's only a very recent invention, and because of that, scientists still don't know much about how this global repository of information is affecting our thinking in the long term. Now new research suggests one side effect of constant access to the web is doubting what we think we know.

In other words, even if you already know what the capital of France is, you're going to look it up online just to be sure - and having the world's accumulated knowledge so conveniently accessible means our brains have a tendency to outsource their thinking even when it's not necessary.

Around 100 people were asked to take part in the study by a team from the University of Waterloo in Canada. When asked general knowledge questions, half the participants were given access to the Internet to look up answers they didn't know, and they ended up being 5 percent more likely to claim ignorance before checking the facts online. The researchers noted this small but noticeable bias towards doubting our own knowledge if the web is available.

And it very often is: the Pew Research Centre recently said that 1 in 5 Americans are online almost constantly, while 73 percent report going online daily. As the Internet is so widespread and readily accessible, scientists think we're naturally starting to offload the job of remembering tasks, dates, memories and facts - we're using the Internet as a group memory or transactive memory that's bigger than any one individual.

"With the ubiquity of the Internet, we are almost constantly connected to large amounts of information," says one of the Canadian researchers, Evan Risko. "And when that data is within reach, people seem less likely to rely on their own knowledge… Our results suggest that access to the Internet affects the decisions we make about what we know and don't know."

Risko and his team speculate that the rise of the Internet may make it less acceptable to say we know something and then get it wrong. It's also possible that the brain rewards the process of looking something up online and getting confirmation, which could be another reason for why we tend to want to refer to the web for our answers.

Their results have been published in the e journal, Consciousness and Cognition. 

So next time you're at a pub quiz, resist the urge to look up the answers online - chances are you probably already know them.