Chapter 6: Couples composed of insecure and unbiased individuals

In this chapter we study couples composed of insecure and unbiased individuals. Thus, the only difference with respect to the case of standard couples considered in Chapters 3, 4, and 5 is that the reaction functions first increase and then decrease with the love of the partner. This implies that the geometry of the two null-clines is different from that in the previous chapters, but that variations of the appeals still shift (vertically or horizontally) the two null-clines. For this reason, the main properties of the couple can still be derived from simple geometric considerations based on the geometry of the null-clines. For simplicity, we study only the case in which the reaction to love increases up to a threshold value of the love of the partner and then declines but remains positive. This implies that the analysis can be performed by looking only at trajectories in the positive quadrant of the space of the feelings because initially non-antagonistic partners remain so forever. Moreover, the reaction to love is described by a function identified by two parameters interpretable as reactiveness to love and degree of insecurity (higher insecurities characterize reactions to love that start declining earlier)…