Bifurcation in the evolution of certainty in a small decision-making group by consensus

Abstract

In a previous paper, the evolution of certainty measured during a consensus-based small-group decision process was shown to oscillate to an equilibrium value for about two-thirds of the participants in the experiment. Starting from the observation that experimental participants are split into two groups, those for whom the evolution of certainty oscillates and those for whom it does not, in this paper we perform an analysis of this bifurcation with a more accurate model and answer two main questions: what is the meaning of this bifurcation, and is this bifurcation amenable to the approximation method or numerical procedure? Firstly, we have to refine the mathematical model of the evolution of certainty to a function explicitly represented in terms of the model parameters and to verify its robustness to the variation of parameters, both analytically and by computer simulation. Then, using the previous group decision experimental data, and the model proposed in this paper, we run the curve-fitting software on the experimental data. We also review a series of interpretations of the bifurcated behaviour. We obtain a refined mathematical model and show that the empirical results are not skewed by the initial conditions, when the proposed model is used. Thus, we reveal the analytical and empirical existence of the observed bifurcation. We then propose that sensitivity to the absolute value of certainty and to its rate of change are considered as potential interpretations of this split in behaviour, along with certainty/uncertainty orientation, uncertainty interpretation, and uncertainty/certainty-related intuition and affect.