The picture that emerges from these theoretical considerations is one of a quilt, some patches of which enlarge at the expense of their neighbors as one code copies more successfully than another. As you try to decide whether to pick an apple or a banana from the fruit bowl, so my theory goes, the cerebral code for apple may be having a cloning competition with the one for banana. When one code has enough active copies to trip the action circuits, you might reach for the apple.
But the banana codes need not vanish: they could linger in the background as subconscious thoughts and undergo variations. When you try to remember someones name, initially without success, the candidate codes might continue copying for the next half an hour until, suddenly, Jane Smiths name seems to pop into your mind because your variations on the spatiotemporal theme finally hit a resonance and create a critical mass of identical copies. Our conscious thought may be only the currently dominant pattern in the copying competition, with many other variants competing for dominance, one of which will win a moment later when your thoughts seem to shift focus.
It may be that Darwinian processes are only the frosting on the cognitive cake, that much of our thinking is routine or bound by rules. But we often deal with novel situations in creative ways, as when you decide what to fix for dinner tonight. You survey what is already in the refrigerator and on the kitchen shelves. You think about a few alternatives, keeping track of what else you might have to fetch from the grocery store. All this can ash through your mind within seconds--and that is probably a Darwinian process at work.
Elements of Intelligence
IN PHYLOGENY and its ontogeny, human intelligence first solves movement problems and only later graduates to ponder more abstract ones. An artificial or extraterrestrial intelligence freed of the necessity of finding food and avoiding predators might not need to move--and so might lack the what-happens-next orientation of human intelligence. There may be other ways in which high intelligence can be achieved, but up-from-movement is the known paradigm.
It is difficult to estimate how often high intelligence might emerge, given how little we know about the demands of long-term species survival and the courses evolution can follow. We can, however, compare the prospects of different species by asking how many elements of intelligence each has amassed.
Does the species have a wide repertoire of movements, concepts or other tools? Does it have tolerance for creative confusion that allows individuals to invent categories occasionally? (Primatologist Duane M. Rumbaugh of the Great Ape Trust of Iowa has noted that small monkeys and prosimians, such as lemurs, often get trapped into repeating the first set of discrimination rules they are taught, unlike the more advanced rhesus monkeys and apes.)
Does each individual have more than half a dozen mental workspaces for concurrently holding different concepts? Does it have so many that it loses our human tendency to chunk certain concepts, as when we create the word ambivalence as a stand-in for a whole sentences worth of description? Can individuals establish new relations between the concepts in their workspaces? These relations should be fancier than is a and is larger than, which many animals can grasp. Treelike relations seem particularly important for linguistic structures; our ability to compare two relations (analogy) enables operations in a metaphorical space.
Can individuals mold and refine their ideas off-line, before acting in the real world? Does that process involve all six of the essential Darwinian features, as well as some accelerating factors? Are there shortcuts that allow the process to start from something more than a primitive level? Can individuals make guesses about both long-term strategies and short-term tactics, so that they can make moves that will advantageously set the stage for future feats?