The interaction between two people, a dyad , will be very different from that which is possible in a three-party relationship, or triad . Size of Group . Simmel considered the size of the group in which social action takes place to be a factor in determining the nature of the group. Here he was concerned with the form of the group, rather than the content of the interaction. In the dyad , a relationship can be considered relatively straightforward, in that each individual can present themselves to the other in a way that maintains their identity, and either party can end the relationship by withdrawing from it.
Various strategies emerge in the triad that change the form of interaction from the dyad.
In the triad, there may be strategies that lead to competition, alliances, or mediation. The self-preservation of very young associations requires the establishment of strict boundaries and a centripetal unity. This implies much greater possibility of individual freedom and flexibility, with the common culture and form of association greatly weakened. The metropolis or city becomes the location where the division of labour is the greatest and where this individuality and individual freedom is most expanded. This is the result of the growth of the division of labour and the specialization in individual pursuits that is a necessary part of this.