Why can we find geometric shapes in the night sky? How can we know that at least two people in London have exactly the same number of hairs on their head? And why can patterns be found in just about any text — even Vanilla Ice lyrics? PatrickJMT describes the Ramsey theory, which states that given enough elements in a set or structure, some interesting pattern among them is guaranteed to emerge — and how it contributes to the formation of conspiracy theories.

Today, there are thousands of cults around the world. Broadly speaking, a cult is a group or movement with a shared commitment to a usually extreme ideology that’s typically embodied in a charismatic leader. But what exactly differentiates cults from other groups – and why do people join them? Janja Lalich describes how cults recruit and manipulate their members.

The desire to belong is a fundamental part of human nature. In this episode of the American Psychological Association’s “Speaking of Psychology,” Geoffrey L. Cohen, PhD, of Stanford University, talks about how feeling like an outsider can harm us; why threats to belonging drive problems as varied as achievement gaps and political polarization; and how to boost people’s sense of belonging, especially among those most at risk of feeling like outsiders.

Next Section »