Abstract: | It is argued that people work on 6 interrelated general problems, called key problems, which are necessarily simply conceived and therefore open to a priori identification. Key problems demand separate attention, and, with children below 9 years of age and again between 10 and 17 years of age, and with adults in long-term groups, they receive attention 1 by 1, as focal problems, with intervening transitional phases, in a fixed sequence. Isolated societies stress 1 focal problem, and families and individuals tend to do the same. Humor and elated play worsen the problem. Brain lateralization helps in separating work on the 1st key problem from work on other problems, and failure to accomplish this contributes to mental disorder. The theory can be fitted to aspects of brain activity (as shown in the electroencephalograph), such as the change with age in theta coherence growth rate. |