sophos scott welcome to the show it's really great to have you with us so let me start of by asking why is laughter important to psychology i mean laughter hasn't been studied for a long time why are scientists getting into it now i think there's probably 2 ounces to that i think 11 on sirius the psychologists neuroscientists a good a lot more interested in positive emotions in general most of the research in psychology into emotions has focused on negative emotions and there's been a general recognition over the last 15 or so years that we need to pay more attention supposed to be emotions and i think secondly. when you still it's pay attention to it actually is a very interesting emotion in terms of how interesting me it's used by humans but also how extremely widespread he says ok so what we're going to actually try to deconstruct in detail wise laughter so peculiar and interesting let's start with gestures like gestures like nodding or finger rocking are different have different meaning from region to region but laughter and smiles there's sort of universal aren't they exactly so as