Goldilocks principle

The Goldilocks principle is named by analogy to the children's story "The Three Bears", in which a young girl named Goldilocks tastes three different bowls of porridge and finds she prefers porridge that is neither too hot nor too cold but has just the right temperature. The concept of "just the right amount" is easily understood and applied to a wide range of disciplines, including developmental psychology, biology, astronomy, economics and engineering.