Scientists have found a delay of as little as as two seconds waiting for material to download on a phone is enough to set our pules racing.

Eirisson and Vodafone monitored the brain activity of 150 volunteers, the results showed even tiny delays or disturbances in the speed at which they access the internet raised their tension levels.

A delay of a second or two in uploading a selfie to Facebook was enough to cause significant stress among users.

Those aged between 18 and 24 found the experience the most upsetting.  The researchers said this group are rthe most uthless when it comes to evaluating the performance of a provider.