This study investigates an under-researched topic: individual-to-individual or team-to-team interactions during the alliance pre-formation phase. We develop a general theory based on the principle of congruity for understanding the micro-dynamics of the alliance formation process. The attitudes of each party in an alliance towards their prospective partner depend on the level of mismatch between their initial evaluations of the contributions of each partner, and on their wish intensity and speed to reach congruity. The impact of different managerial cultural backgrounds (special theory) and mind-sets (special theory application) are theorised. Further applications are considered and all are presented as testable propositions.