i am working on a research proposal with the aim of conducting a research on the above topic. My focus on the extracurrricular activities include religious, social, educational, physical and social activities.
It would be useful to look at the research by my colleagues Kath Woolf and Chris McManus from UCL exploring the concept of social networks and social capital on academic achievement. They have mainly looked at medical students but have some very interesting results with more in the pipeline about how social networks and subsequent social activities may relate to academic achievement. See also PhD by Suzanne Vaughan - I think she recently published something in Medical Education.