The Interactance Hypothesis: A Gravity Model Fitting Physical Masses and Human Groups

T HE HYPOTHESIS of interactance predicts the number of interactions, of any one specific kind, among people when observed in groups, from their basic dimensions of time, space, population and per capita activity. This dimensional principle of human interacting can be roughly stated in folk terms (to be more exactly defined below) as: "Groups of people interact more as they become faster, nearer, larger, and leveled up in activity." Conversely, people will interact less in proportion as their groups (a) have fewer actions per period, (b) are further apart, (c) are smaller in population, and (d) are more unlike each other in average activity. The hypothesis thus states the factors determining the quantity of group interaction regardless of its quality or form, i.e., regardless of whether it is cooperating, competing, conflicting, or engaging in some other form of interaction. Whether these sub forms of interacting, or social processes, will require differential coefficients in the interactance formula, Eq. I, is unknown as yet. For testing, the hypothesis must be stated more formally in exact operational terms. Since the factors or dimensions of group interactance parallel the dimensions of physical gravity, the formal statement here will have the same form or formula for both, but with the factors expressed in appropriate physical or social units. Thus one factor in the formula will be in units of particles,