Why do people even check their mobile phones regularly when they are together with other people? So, what is the reason that we have so many "phubber"? This study shows the explanatary power of FoMO ("Fear of Missing Out") for this behaviour. It's the fear to be left out, to miss out important things that make people almost addicted to their phones. However, interesting differences can be found between males and females, especially in their checking behaviour when they are in company.