Born around the same time as the commercial Internet, today’s emerging adults are the Internet generation, with the vast majority engaging frequently with their real-life peer groups through online social networks. Emerging adulthood is a critical period for the development of psychiatric disorders, so learning about these interactions is crucially important to our understanding of the origins of mental health and wellbeing. If we are to understand social influences on mental health and disorder in this or future generations of adults, then we must take notice of this online, as well as offline social activity. Fortunately, whereas offline social networks are difficult to assess and track, for this age group online social networks are detailed, ecologically valid databases of real time social activity. We are asking participants to provide us with their Twitter username and permission to download and anonymously analyse their publicly available tweets, to help us to understand changes in psychological wellbeing during emerging adulthood.