It's official! Cellphone use is contagious

Using a cellphone is contagious, according to a new study which found that a person is twice as likely to talk on a mobile, or check for messages, if a companion did the same.

Females are more likely to use their cellphones than men because it was more 'integrated into the daily lives of women', researchers said.

"What we found most interesting was just how often people were using their mobile phones. Every person we observed used his/her phone at least once while one woman was on hers about half of the time," said Dr Daniel Kruger, the study's co-author from the University of Michigan.

"Individuals may see others checking their incoming messages and be prompted to check their own," Kruger said.

In the study, almost two dozen students in two groups, were observed "unobtrusively", who were seen socialising near an unnamed university campus, The Daily Telegraph reported.

Researchers recorded every moment a person used their mobile phone in dining halls and coffee shops around campus between January and April last year.

Kruger, from the university's School of Public Health, Population Studies Center and the Institute for Social Research, said the study found when one of the group used their mobile phone, their companions were more likely to follow shortly after.

Overall, the students used their phone on average a quarter of the intervals but, significantly, this increased to almost 40 per cent when their companion had just used their device during the previous 10-second interval.

Kruger believes this pattern could be related to the effects of "social inclusion and exclusion".

"If one person in a pair engages in an external conversation through their phone, his or her companion may feel excluded. That companion then might be compelled to connect with others externally so as not to feel left out," he said.

"We need to get smart about smart phones. They can be a wonderfully useful technology, but we need to use them more carefully to make sure that they do not interfere with our in person social interactions," Kruger told the paper.

The study was published in the Human Ethology Bulletin journal.