You need calculus to find instantaneous acceleration at a point, not the cumulative behavior over time, which can be done with ordinary calculation. Integration gives you the area under the curve, which is not simply the reverse. You can't relate this concept to human behavior, even if you did understand it. Nobody really knows the exact linkages between individual and collective behaviors. Behaviorists don't even come close to understanding either of them properly. One thing is for sure, if there is a fundamental theorem, behaviorists won't find it. This idea of thresholds merely restates the problem. At some point, someone decides to "go with the flow" and group action takes place. Now what? Where do you go from there? Back to square one is my guess.