Summativity

1. A property of a system such that a change in each element depends only on that element itself. Each element can therefore be considered independent of the others. The variation of the total complex is then the sum of the variations of its elements.

2. In the mathematical sense, summativity means that a change in the total system obeys an equation of the same form as the equations for the parts.

3. In biological, psychological and sociological systems the interactions between the elements may decrease with time so that they can be neglected, in which case the system becomes progressively more mechanical and segregated, tending to behave like the sum of the independent parts.