Abstract
The present paper illustrates the breadth of research methods in the Social and Behavioural Sciences and how these may be applied to the issue of environmental microplastics. Microplastics are a human-caused problem and we need to understand the human dimension in order to address it. Nine key points are emphasised in this paper and follow from the key observation that humans, through their perceptions, decisions and actions, are pivotal to the issue of primary and secondary microplastics in the environment: (1) human perception and behaviour can be subject to systematic and rigorous scientific study, using theory-based hypothesis testing, measurement and statistical analysis; (2) qualitative methods can explore new areas of research and provide novel, in-depth insights; (3) best practice and recommendations exist for measuring social data; (4) quantitative cross-sectional approaches can test how important social factors are for key outcomes (e.g., the role of perceived risk, values, social norms for behaviour); (5) experimental quantitative approaches can compare randomised groups and study cause–effect relations; (6) certain limitations and challenges are unique to research with people; (7) communications and interventions (e.g., change campaigns, new regulation, education programmes) should be developed based on scientific insights into human thought and behaviour and then evaluated systematically; (8) social researchers should work towards developing standardised tools and protocols; and (9) social research on microplastics and its determinants is in its infancy and a number of important research questions remain to be addressed.