The QWERTY keyboard was originally designed to prevent typewriter jams by spacing out letters that often appeared close together in sentences, but it's now shaping our feelings towards certain words, new research has found.

It's all to do with emotions: words with more letters from the right-hand side of the QWERTY keyboard tend to have more positive associations, as has been established by several previous studies. This so-called QWERTY effect is even having an impact on the baby names we're choosing.

It's believed that because characters on the right of a keyboard are easier to type (for right-handed people, which is most of us), we make a positive association with them in our minds. 

In the latest study, a pair of researchers from Germany and Switzerland found evidence of the same QWERTY effect all across the web by studying millions of product names, book and film titles across 11 popular websites, including Amazon, YouTube, and Rotten Tomatoes.

On nine of the sites, products and items with more characters from the right-hand side of the QWERTY keyboard tended to have more positive reviews, as Chris Baraniuk from New Scientist reports.

What's more, those positive reviews used more letters from the right side of the keyboard, too. "[The QWERTY effect] started appearing in one data set after another," said one of the team, David Garcia from the Swiss Federal Institute of Technology in Zurich.

That means there's evidence of the phenomenon both at the point of decoding (the way we interpret text) and at the point of encoding (creating text ourselves, in this case, the online reviews).

Positive reviews don't necessarily equate to success, though. The top-selling items on Amazon don't show any evidence of the QWERTY effect, the researchers found.

"To the best of our knowledge, this is the first work to reveal the extent to which the QWERTY effect exists in large scale human-computer interaction on the web," Garcia and his colleague Markus Strohmaier, from the Leibniz Institute for the Social Sciences in Germany, write in their final report.

The pair published their findings on arXiv.org and made them available for other researchers to study via GitHub. The research has also been presented at the International World Wide Web Conference in Montreal, Canada.

While the findings are yet to be peer-reviewed, they represent the first large-scale study of the QWERTY effect. Further research is now needed to establish whether there truly is a causal relationship between QWERTY and our attitudes towards words, not just a random link.

But until then, be sure to pay attention to how you're typing out your sentences – it just might affect your mood.