In line with the view of most psychologists and psychometricians, Burkart et al. assume that there is a single general intelligence (g); controversy centers around the identity and nature of domain-specific computational capacities and the extent to which nonhuman animals can be said to have a g-like capacity.

Over the past several decades, researchers have challenged this consensus and developed alternative ways of conceptualizing human intellect (Guilford Reference Guilford1967; Sternberg Reference Sternberg1984). In my case, I deliberately disregarded paper-and-pencil instruments of the sort favored in scholastic settings, and which almost always yield a “positive manifold.” Instead, culling evidence from a range of disciplines – from anthropology and education to neuropsychology and evolutionary biology – I put forth the claim that human beings are better described as having a set of relatively independent computational capacities, which I termed the “multiple intelligences” (Gardner Reference Gardner1983/2011).

According to my analysis, the kind of intelligence typically measured in IQ tests is scholastic intelligence – the bundle of skills needed to succeed in modern secular schools. In my terms, success on such instruments depends on a combination of linguistic and logical-mathematical intelligences, with spatial intelligence sometimes tapped as well. It is worth noting that, at the extremes, strength (or weakness) with one of these intelligences does not predict comparative strength (or weakness) with the other (Detterman Reference Detterman1993). Largely ignored in standard measures of intellect are several other intelligences that I identified: interpersonal and intrapersonal intelligences (often described as social or emotional intelligence), musical intelligence, bodily kinesthetic intelligence, and naturalist intelligence. Because we do not have comparable instruments to assess nonscholastic intelligences (but see Gardner et al. Reference Gardner, Feldman and Krechevsky1998), we do not know to what extent ability in, say, musical intelligence correlates with strength (or deficits) in, say, social or intrapersonal intelligence. Yet ample evidence confirms that these intelligences can be dissociated from one another, as happens with prodigies (Winner Reference Winner1997) or individuals on the autistic spectrum (Silberman Reference Silberman2016). Put differently, ability to succeed in school settings is decreasingly important, as one ventures to contexts that differ significantly from the canonical Western school.

Even as MI theory differs from a g-centric view of the world, it also differs from Fodorian modules. Intelligences may contain specific modules (e.g., linguistic intelligence may contain a parsing or phoneme discrimination module), but their exercise in the world is far less reflexive, far more adaptive. An individual skilled in linguistic intelligence is able to speak, write, communicate, and learn new languages and the like. Skill in spatial intelligence involves making sense of local two-dimensional arrays, as well as navigating around a neighborhood or, indeed, around the globe.

It may seem that the intelligences are a grab-bag of primary Fodorian modules as well as more-general secondary information-processing or problem-solving capacities processing certain kinds of content. And, indeed, as we attempt to make sense of human cognition, that characterization proves serviceable. MI theory stands out less in terms of the precision of its claims with respect to the execution of tasks in the world than in its challenge to the notion that there exists any sensible and defensible notion of general intelligence – even within Homo sapiens.

For those sympathetic to an MI view, formidable questions remain. What are the basic building blocks of intellect? To what extent is each heritable? How do strictly modular capacities interact with ones that are more permeable? Do we need to posit a separate “executive function,” a so-called “central intelligence agency,” or does such a capacity emerge naturally out of intrapersonal intelligence (the ability to know oneself accurately) and logical intelligence (the ability to reason about one's actions)?

An MI perspective yields far more specific pictures of how human beings carry out the raft of tasks for which the species has specifically evolved as well as those tasks that have emerged over the centuries by virtue of newly emerging cultural artifacts and technologies, and, perhaps, acts of nature (e.g., diseases, volcanic eruptions). Furthermore, such a perspective suggests an alternative approach to the issue addressed in the target article.

Instead of invoking g, plus specific modules, one can instead break down any task in terms of its demands on specific intelligences (e.g., playing chess involves logical and spatial intelligence but little bodily or musical intelligence) as well as the various ways in which one can become proficient at the task (e.g., some chess players weigh interpersonal intelligence – knowing the opponent – much more than do others). We avoid the conundrum that human intelligence is most naturally assessed through language-based instruments, and yet such instruments cannot be employed with other animals – leaving us with a situation where we can do species comparisons only by eliminating what is widely regarded as the essence of human intellect. By the same argument, we cannot use “musical intelligence” of birds, or the “echoing intelligence” of bats, again ignoring a dominant intellectual capacity. More generally, we may be better able to trace the similarities and differences between human beings and particular species (be they birds, bats, or dolphins) if we think of them in terms of each species' own dominant and less salient intelligences, rather than their having more or less of g.