How We Perceive the Weather

A new study looks at how ideological and political beliefs affect people's perceptions of the weather. The authors surveyed 8,000 people across the U.S. between 2008 and 2011 and found that while floods and droughts were remembered correctly, temperature changes were a different story. From Ars Technica:

In fact, the actual trends in temperatures had nothing to do with how people perceived them. If you graphed the predictive power of people's perceptions against the actual temperatures, the resulting line was flat—it showed no trend at all. In the statistical model, the actual weather had little impact on people's perception of recent temperatures. Education continued to have a positive impact on whether they got it right, but its magnitude was dwarfed by the influences of political affiliation and cultural beliefs.

And those cultural affiliations had about the effect you'd expect. Individualists, who often object to environmental regulations as an infringement on their freedoms, tended to think the temperatures hadn't gone up in their area, regardless of whether they had. Strong egalitarians, in contrast, tended to believe the temperatures had gone up.

Minority Rules: Why 10 Percent is All You Need

What does it take for an idea to spread from one to many? For a minority opinion to become the majority belief? According to a new study by scientists at the Rensselaer Polytechnic Institute, the answer is 10%. Once 10% of a population is committed to an idea, it's inevitable that it will eventually become the prevailing opinion of the entire group. The key is to remain committed.

The research was done by scientists at RPI's Social Cognitive Networks Academic Research Center (SCNARC), and published in the journal Physical Review E. Here's the abstract:

We show how the prevailing majority opinion in a population can be rapidly reversed by a small fraction p of randomly distributed committed agents who consistently proselytize the opposing opinion and are immune to influence. Specifically, we show that when the committed fraction grows beyond a critical value pc=10%, there is a dramatic decrease in the time Tc taken for the entire population to adopt the committed opinion. In particular, for complete graphs we show that when p<pc, Tc~exp[a(p)N], whereas for p>pc, Tc~lnN. We conclude with simulation results for Erdos-Rényi random graphs and scale-free networks which show qualitatively similar behavior.