The experimental study has revealed that the manner of thinking under conditions of group (diadic) problem-solving depends on the correlation of intellectual, capacities of the partners, on the modality of their interassessments, on their situational activity and role positions. Two extreme types of relations in the diad can be established: common (shared) and individual solving. The first is typical of intellectually active partners and occurs when inter-personal emotional assessments are positive. The second develops when partners are intellectually passive while both explicit and implicit emotional attitudes between them are negative.