Stepping towards causation in studies of neighborhood and environmental effects: how twin research can overcome problems of selection and reverse causation.

Address: Department of Epidemiology, University of Washington, Seattle, WA 98195, USA; Interdisciplinary Graduate Program in Nutritional Sciences, University of Washington, Seattle, WA 98195, USA. Electronic address: [email protected].; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA.; Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA.; Department of Urban Design and Planning, Urban Form Lab, University of Washington, Seattle, WA 98195, USA.; Interdisciplinary PhD Program in Urban Design and Planning, Urban Form Lab, University of Washington, Seattle, WA 98195, USA.; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA; Department of Urban Design and Planning, Urban Form Lab, University of Washington, Seattle, WA 98195, USA.; Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA.