You only need to look at, and listen to, people around you, particularly children and adolescents, to appreciate that consumer culture has a powerful psychological impact. Celebrities, fashion models, media stars, even computer game heroes and toys, inﬂuence who they aspire to be and what they want to look like. Having the “right” things has become vital, not so much because of these material goods themselves but because of hoped for psychological beneﬁts: popularity, identity, happiness. I have found this psychological impact so intriguing that I started to study it over 20 years ago, and have continued ever since. This book summarises my whole research programme.