“…One of the most discussed contributions pertains to greater levels of discounting among substance abusers than non-drug-using controls. For instance, increased discount rates have been shown across a variety of substances, including alcohol (Petry, 2001a;Vuchinich & Simpson, 1998), cocaine (Coffey, Gudleski, Saladin, & Brady, 2003), heroin (Kirby, Petry, & Bickel, 1999), nicotine (Baker, Johnson, & Bickel, 2003;Bickel, Odum, & Madden, 1999), and opiates (Madden, Bickel, & Jacobs, 1999;Yi, Buchhalter, 1 This is, of course, a simplification of one element of the argument laid out by Plato in the allegory. However, it is unnecessary to fully develop his argument in order to highlight how the idea of shadows can illuminate our understanding of psychological processes.…”