After asking fact-based questions to people from various countries, cultures, and education levels across the world, Rosling discovered that the same wrong information and misconceptions exist everywhere. Humans, regardless of race, class, gender, age, religion, or any other society-constructed classification, all have a tendency towards believing misinformation. All of our brains evolved out of the same hunter-gatherer civilization characterized by identical fears and instincts. People are more alike than they are different.

We all form opinions about the world based on our experiences, and we assume experiences elsewhere are either the same (the generalization instinct) or vastly different (the gap instinct) from our own. We do this in order to make sense of the world. We believe our opinions are reality because we want to think our brains have no reason to lie to us. As a result, we misinterpret experiences that differ from our own. For example, people from cultures in which love matches are made often believe that arranged marriages are a confining and antiquated ritual, and those from cultures where arranged marriages are commonplace cannot understand why people would leave such an important life choice to chance. Unless we broaden our horizons by traveling and challenging our beliefs, we will never learn any different.