Gardner asserts that each intelligence should be measurable to some extent by psychometric tests. However, he also criticizes the overreliance on such tests in traditional intelligence testing. Psychometric support means that standardized tests should be able to reliably measure and differentiate between the various intelligences. This criterion is important for validating the theory within the scientific community and for practical applications, like educational assessments. It ensures that the concept of multiple intelligences is not just theoretical but has practical, measurable implications.