I heard on the radio about a study which had determined that the average mobile phone user checks their phone every six minutes. The radio presenters stopped to think about how often they check their own phones and realised that they had checked them more than once in the past several minutes of the programme. Unfortunately, I didn't find out who conducted the study and I didn't get to listen to any more about it because I was in bed at the time and I feel asleep.
While I haven't yet found anything more about the study, I don't find its results to be impossible to believe. I wrote about a link about obsessive phone checking in this post, and in my own experience, on more than one occasion I have been annoyed when someone has been playing with their phone while I or another person was talking to them.
The study also made me think about how often I check my own phone. On average, I check it every half an hour, but if I'm engaged in a conversation with someone I don't check it at all, and that could be for hours depending on who I'm talking to. Unless I have a legitimate reason, I won't prioritise a device over a person.