Fig. 4. In societies with little difference among individuals and high peer pressure, the response of public attitude to an increase in perceived problem size is predicted to be discontinuous. When the problem is perceived to be small (and the perceived pay-off of taking action is low), the attitude of most individuals is passive with respect to the problem. Society abruptly shifts to a predominantly active attitude (creating political pressure to regulate the problem) when the perceived severity of the problem has grown sufficiently to reach a critical point (F1). If, subsequently, the severity of the problem is reduced, the active attitude toward regulation remains until another critical threshold point (F2) is reached where an equally abrupt transition to a passive attitude occurs. (From Scheffer et al. 2003.)