Intellectual development means the growth of a child's ability to think and reason. It's about how they organize their minds, ideas and thoughts to make sense of the world they live in. The government of Vietnam requests the education sector to develop hidden competencies of students, particular young learners. This study therefore analyses associated literature to propose a framework to assess the intellectual development and competence of Vietnamese students based on Sternberg's triarchic theory of intelligence. The paper discusses the theory of multiple intelligences and types of intelligence; the development of assessment framework, development path and tools to measure students' intelligence and capacity; and test results on intellectual ability and capacity development of students.