Multiple Intelligences is a theory put forth by Howard Gardner that says that we don’t all learn or think in the same way. Instead of us all having a single, standard brain equally capable of all functions, he says that what we really have is a collection of abilities with our own, unique combination of strengths and weaknesses.
Those abilities fall into categories such as musical–rhythmic, visual–spatial, verbal–linguistic, logical–mathematical, bodily–kinesthetic, interpersonal, intrapersonal, and naturalistic. Existential and moral abilities are sometimes included, too.
I find this theory somewhat useful when helping others learn something new. Some like to read the instructions, some like to see how it is done, others like to physically attempt it, some like to work in teams, some by themselves, and so on. We experimented quite a bit with it at the children’s museum in DC along with other learning theories. When you know how someone is good at learning, you can tailor your approach to them and get that much further along.
Others consider it unsubstantiated hogwash, of course.