Communication is both an activity in which we participate and the means by which we participate in a range of other activities. Therefore, the ability to communicate (or ‘communication capacity’) is closely linked with the ability to participate in life activities and in society. Cohort studies that consider communication capacity and explore participation in life activities provide an opportunity to understand these links at a single point in time or longitudinally. This chapter introduces the reader to four Australian cohort studies: Longitudinal Study of Australian Children (LSAC), Longitudinal Study of Indigenous Children (LSIC), Building a New Life in Australia: The Longitudinal Study of Humanitarian Migrants (BNLA), and the Australian Census of Population and Housing. The WHO's International Classification of Functioning, Disability and Health (ICF) is used as a framework to examine links between communication and participation. The chapter presents communication and participation data from the four cohort studies for children and adults who have speech, language and communication needs (SLCN), as well as people who are Indigenous (First Nations), multilingual and migrants, to reflect strengths and capacity within communities and societies.