The article at the theoretical and empirical levels discusses the peculiarities of the relationship between functional asymmetries of the cerebral hemispheres of younger schoolchildren with the cognitive style « impulsivity-reflexivity. The main approaches to studying this issue in domestic and foreign studies are characterized, a conclusion is made about the relevance of its consideration. The study used the device Activacyometer-6 (Yu.A.Tsygareli) and the technique “Choosing a paired figure” (J.Kagan). The study made it possible to establish and clarify the existence of differences in the processing of information by the left and right hemispheres of the brain, as well as to confirm the existence of a certain connection between the functional asymmetry of the hemispheres with such manifestations of cognitive style as “impulsivity – reflexivity” In particular, it is given that the existence of individual differences (5% level is significant) in the speed of decision-making leads to the fact that children, who are characterized by left-sided hemispheric organization, have “reflexive” signs, make decisions slowly, are prone to analytical means of categorization, are more attentive to individual details, better control their behavior, use more productive means of solving problems and perform tasks with the least number of errors. On the contrary, children who have right-sided asymmetry demonstrate a thematic means of categorization, they are characterized by manifestations of impulsivity, they are less attentive, hyperactive in their actions, give very quick answers, most often focusing on the influence of momentary emotions. The investigation led to the conclusion that in certain conditions of uncertainty, when it is necessary to make the right choice from a number of alternatives, impulsive subjects made their choice quickly, without careful study of alternative options. In turn, reflective subjects, on the contrary, made their decisions on the basis of careful study of all. Pros and cons, while using more productive ways to solve problems.