The document discusses the triune theory of brain evolution and its potential applications in developmental disorders. The triune theory proposes that the vertebrate brain can be divided into three main structures - the reptilian brain, limbic system, and neocortex - which evolved sequentially. This theory provides a framework for better understanding brain functioning and classifying behaviors. It may allow for a three-dimensional model of intelligence consisting of object, emotional, and social components. The document suggests this theory could improve the assessment and diagnostic criteria for autism by recognizing deficits in social and emotional skills/intelligence.