A core reason why recent hits like Flappy Bird and Threes found success -- and are massively addictive -- lies in the way they put us in a unique zen-like state known as flow. Nick Statt was a staff ...

This article originally appeared in longer form in bioGraphic. Every spring, as the daylight lengthens and the weather warms, rivers of birds flow north across the Midwest. They fly high and at night, ...