A law of dominance of informational metabolism types by Ego functions is formulated, which describes the second, after the coefficient of relative intensity of intertype relationships, the level of interaction of informational metabolism types in different intertype relationships. It is demonstrated that the number of IMTs dominant by their first and second functions is equal – in other words, biosocial dichotomy of the Socion is discovered. Based on this law, it is demonstrated that the intertype relationships are in their overwhelming majority asymmetric in principle. A concept of intensity of influence of one type on the other in any pair of intertype relationships is introduced. 17 sublevels of intensity of influence are described.

Key words: socionics, informational metabolism type (IMT), EGO block, functions, dominance, law, intertype relationships, level of interaction, asymmetry, influence, intensity, sublevels.