Hello fellow Psych degree person . I would never even THINK about going so far as finance , but work , budgeting and costs wouldn ' t be too hard . Obviously it takes a lot of work for a child to understand the concept of longterm vs . shortterm gains , but explaining how much money you have and what you need to spend it on isn ' t that hard . I ' m pretty sure my parents successfully explained that to me when I was four and asked them why can ' t you just buy more money so we can go to Disneyland ? And still I wouldn ' t say it ' s the fault of the childteenage brain for not understanding these things . It ' s more that schools and parents don ' t go out of their way to teach these concepts early enough and often enough to prepare the mind for such things .