22:32DiscoveryWhy do people shout on their cellphones?BBC World Service Duration: 27 minutes Mon 5th Sep 2016, 22:32 on BBC World ServiceAvailable for over a yearListen nowWhat causes traffic jams? And why do people shout on their cellphones? Show more GenresFactualScience & NatureFormatsMagazines & ReviewsBrandDiscovery Source: BBC Online