A study by Harvard University shows online complaints rise every time a new version is released. Researchers discovered that Google searches for phrases such as ‘iPhone slow’ spike whenever a more expensive type of the device goes on sale.

In contrast, they found there were no such patterns for rival products such as the Samsung Galaxy.

Professor Sendhil Mullainathan said: The results are, to say the least, striking’. However, he warned that the perception of a phone ‘slowing down’ may be purely psychological.

The study bases itself solely on results of Google searches. (also, that's the kind of research some professors are spending their time on these days? wow.)