A little bit of knowledge can go straight to your head, and not in a good way. New research has found that those who only read snippets of their Facebook newsfeed often think they know more than they actually do.

By glancing through article previews, instead of reading the full piece, many users overestimate their understanding of an issue, and this is especially true for those whose knowledge is guided by strong emotions - and, therefore, strong opinions.

"Because most social media users only have a passing engagement with posted news, exposure to political information on social media may simply create the illusion of political learning," write the researchers at the York College of Pennsylvania.

The study split nearly 1,000 participants into three groups to measure how much knowledge they had gained on an issue, and how much knowledge they thought they had gained.

Each group was given the news in a slightly different format, and all participants were asked to fill out a survey that measured their cognitive styles.

The first group (320 participants) was asked to read through a full article from The Washington Post about genetically modified (GM) foods. The second group (319 participants) was given a Facebook newsfeed with four article previews, one of which featured the same GM article.

The third and last group (351 participants) was given no information at all.

To assess their level of knowledge about GM foods, participants were given six factual questions, with five answers that could be found embedded in the article, and three answers that could be found in the Facebook preview.

To measure their level of confidence, the participants were also asked to estimate how many questions they got right.

Unsurprisingly, those who read the full article answered the most questions correctly, while those who read the preview scored only one more correct answer than those who were given no information at all.

Additionally, the findings suggest that people who read only the previews were far too confident in their knowledge. What's more, those participants whose cognitive style is more guided by emotion, tend to be more certain of their rightness.

This "need for affect" essentially means that participants have strong gut reactions or intuitions that they don't question. In other words, the feeling of being accurate is more satisfying for many people than actually being accurate.

"Those who are more driven by emotion allow the positive feelings associated with being right to override the need for actual accuracy," the authors write, "thus coming away from limited exposure to information falsely overconfident in their knowledge of the subject matter."

Unfortunately, this false confidence may have serious repercussions. Not only does it make users more susceptible to fake news and misinformation - a burgeoning issue in the modern day and age - it could also make them more polarised and politically uninformed.

Today, 67 percent of Americans get their news from social media. As such, Facebook has become an important source of political information, but is it a source of political understanding?

This study certainly suggests it is not. The average Facebook user only clicks on about seven percent of the political news stories in their feed, which means that the vast majority of the time, people are getting tiny little doses of information, with a big old dose of misguided confidence.

"As Facebook is increasingly relied on as a news source, audiences' overconfidence could be potentially troublesome, especially if the perceived knowledge gain is based on misinformation," the authors conclude.

This study was published in Research and Politics.