Results of children of preschool age tested by a method of "play at guesses" were compared with data obtained on healthy adults, and on adult subjects affected with schizophrenia and oligophrenia. It has been revealed that part of subjects of all groups notice sequences of signals in the experimental cyclic environments. Stochastic environments were found to provoke the effect of levelling off the rates of predictions. It is assumed that man relies in all his milieus not on the rate but on the sequence of signals. This capacity connected with the ability to store behavioral information starts developing from 6 years of age. Behavior of children aged 4-7 and of oligophrens in all milieus is typically alternating.