The authors characterise the dynamics of social change by empirically demonstrating the uptake of minority behaviours by a majority of the population. They find that if a minority-held behavior can reach a threshold of 25% of the population, it consistently shifted the conventional behavior.
The social norms, opinions and behaviors of a population can rapidly change under certain conditions; for instance, the change in acceptance of gay marriage by a majority of the US population in a relatively short time period. Shifts in behaviors are called tipping points, a term with long use in sociology and more recently popularised by the publication of a book by Malcolm Gladwell. In a recent article published in Science the authors model and then empirically test population thresholds or “critical group size” required for an active minority group to change the behaviour of the majority.
Their theoretical model based on population size, memory and an affinity towards social coordination, predicted that as a behavior of a population neared 25%, the greater likelihood it would reach a critical mass and quickly become the dominant behavior. The authors tested these predictions in experimental trials where social conventions were established in an online community by incentivising coordination among participants. They then introduced a “committed minority” of players into the online community to attempt to overturn the prevailing behavior by offering alternative behavior. The experiments replicated the findings of the model. When the behavioral minority was equal to or above 25% of the population, the majority was significantly more likely to adopt the alternative behavior than those trials with a committed minority of under 25%.
The implications of this work for conservation psychology are evident as many of us are focused on changing behaviors. In attempting to instigate rapid adoption of sustainable behaviors in more homogenous communities, a 25% threshold provides a target to aim for. Of course many in the conservation community work in more heterogeneous populations than online communities and the behaviors we are attempting to change may be socially, psychologically, and/or economically important.