Scheme is a term put forward by psychologist Jean Piaget. It refers to cognitive structures (pervasive thought patterns) that first appear during childhood and help children organize knowledge. This, in turn, helps them learn ways to view, understand and interpret the world around them, and then to adapt to the demands of that world.
For instance, a child that grows up in a loving home and a safe environment will learn a “scheme” that views the world as a benign place, where a child that grows up in a violent and unpredictable home will grow up viewing the world as a dangerous place.