Final answer:
Howard Gardner added Existential intelligence to his theory of multiple intelligences.
Step-by-step explanation:
In Howard Gardner's theory of multiple intelligences, he added Existential intelligence to his list of intelligences. This type of intelligence reflects a person's ability to use intuition, thought, and meta-cognition to ask (and answer) deep questions about human existence.
Gardner's theory proposes that there are eight intelligences: linguistic intelligence, logical-mathematical intelligence, musical intelligence, bodily kinesthetic intelligence, spatial intelligence, interpersonal intelligence, intrapersonal intelligence, and existential intelligence.