This paper is based On the basis ofon the author’s understanding of abilities, according to which abilities are unfolded revealed in three dimensions as the abilities of an individual, of a subject of activity (agent) and of personality, and the development of abilities occurs in these dimensions as well. The aAbilities of a human as an individual reflect his or her natural (biological) essence. The aAbilities of a subject of activity develop on the basis of individual abilities by means of acquisition of intellectual operations. The aAbilities of personality are viewed as the abilities of a subject of activity under moral control. Defined by personal abilities and meanings they become spiritual abilities. Thise article sets puts forward the results of the study of reflective mechanisms in the process of development of abilities through intellectual operation acquisition. 138 students of the middle school № 507 took part in the study. The test of developed by A.B. Karpov (2003) was used for the diagnostics of the level of reflexivity development. Students of experimental grades and control grades took part in the study. In eExperimental grades students had classes on the acquisition of intellectual operations. In For control grades there were no special classes. Study was undertaken in the 4^th, 6^th and 10^th grades. The results of the study showed that the level of development of reflexivity in the 6^th and 10^th grades is no higher than in the 4^th grades students. The goal-oriented teaching of intellectual operations led to a statistically significant advance in reflexivity in the 6^th and 10^th grade students. A cComparison of students’ IQs and reflexivity showed interdependence. A cComparison of the reflexivity index and the reflection of different intellectual operations showed statistically significant correlation.