In article are described main results of the study of creative problem-solving tasks (CPS) with sudden insights for various age-specific periods. A classification of testing tasks was developed referencing thinking methods leading to creative solutions such as addition, modification, unification and transformation. This set of creative problem-solving tasks was offered to 7 groups of 200 children age 3 to 15 and 50 adults. Early insights were found in 4-year olds’ work on very simple tasks. Data indicate that the dynamics of CPS skills development varied by the age cohort.