Seite - 123 - in Psychoanalytic Perspectives on Puberty and Adolescence - The Inner Worlds of Teenagers and their Parents

Development of thinking 123 The aspects I will now describe are: formal operations, abstract thinking and deductive reasoning, and complex thinking (metaphor and sarcasm). Formal operations The major qualitative change in thinking occurs between latency (ages 6 through 11), where the child thinks in concrete operations, to the formal operations of the adolescent. With concrete operations, the child can solve simple tasks according to logic and systematic rules, but only in adolescence can he identify the reasons for systematic operations, as well as their results. Inhelder and Piaget (1974) dem- onstrate this using the well -known example of the “pendulum problem”: Children or adolescents are shown a pendulum consisting of a weight hang- ing from a string and set into motion. They are then posed the question: upon what does the speed of the pendulum depend – is it the heaviness of the weight, the length of the string, the height from which the weight is set in motion or the force with which it is pushed? The children are given various weights and strings of various lengths to use in their deliberations, and the ways latency children and adolescents solve this problem can be compared. In concrete operations, latency children tend to approach the problem with ran- dom attempts – often changing more than one variable at a time. For instance, they may try the heaviest weight on the longest string, dropped from an interme- diate height with medium force. Then they might take a medium weight on the shortest string and swing it with medium strength. When the pendulum’s speed is altered, latency children have no way to say what caused the change, since they altered more than one variable at the same time. Even when they find the right answer (the length of the string), they still cannot explain why this is. Indeed, Piaget devised his experiment in order to distinguish between the correct result and the explanation for it. An adolescent – who can use formal operations – employs a form of hypotheti- cal thinking to solve this problem, as in an scientific experiment. The thought pro- cess involved could be described as follows: “Let us first examine weight. I will try out various weights and keep all the other variables constant (length of string and height).” (The adolescent would do this and then see that there is no differ- ence.) “Now, I will try out different lengths of string, leaving the other variables constant. Yes, now I see a difference – the pendulum swings faster with a shorter string: thus, the length of string does make a difference. But let me try height, too: no change; then force: no change either.” (Piaget speaks here of the capacity to exhaust all combinations.) “But I will still try out a different height, and also a different strength of pushing the weight at the outset. No, I see no difference as a result. This means that the speed is solely dependent on the length of the string.” Through this process, the formally operational thinker arrives at an answer that is not only correct but can also be explained and defended. This is why Piaget