Once upon a time, intelligence was the purview of taxonomy.  “These animals are smart.  Those animals are not.  Make a taxonomic classification along those lines.”  This is literally putting the cart before the horse – assuming a conclusion, then organizing and sorting the data thusly, to come to that conclusion. 

People created intelligence tests based on detecting what they valued as intelligent and applied them to favorite target subjects of the day to find Boolean, “Intelligent” or “Non-Intelligent” beings.  It would not be too far fetched to imagine speaking to a poor, hungry, cold, caged chimpanzee in Latin and grading its intelligence via the response.  This article will not go into the specifics on the historical tests applied and the ensuing historical intelligence ratings on various species, races, and nationalities besides to state that such things were done and may still continue to be done today.

The current simplified stance on intelligence vis-à-vis the brain is that it evolved hierarchically towards higher intelligence with newer, outer layers.  The latest and outermost-layer is the neocortex that wraps around the brain.  It shows up in higher order primates and humans only and is responsible for language, abstract thought, and creativity.  Below that is the limbic system including the hippocampus and amygdala that modulate our behavior.  It shows up in higher order primates and mammals only.  The oldest and innermost layer is the reptilian brain that includes the brainstem and cerebellum.  It shows up in higher order primates, mammals, and lower order animals and is responsible for breathing, heartbeat, balance, and body temperature.  Implicit among this framework is that more brain parts (e.g. more human-like) allows for more intelligence while fewer brain parts (i.e. reptiles only have a reptilian brain) makes for no intelligence. 

Recent research appears to challenge this assumption.  As reported in the New York Times, reptiles appear to be able to perform many of the same cognitive tasks once thought the reserve of higher order mammals.  Prior research initially showing reptiles were incapable of navigating food mazes or mastering the various Pavlovian conditioning exercises that mammals routinely master may have been due to inappropriate tests of physical prowess (e.g. a snake cannot use its arms to open a box), inappropriate tests of reactions (e.g. rodents run and hide from bright lights and sounds; reptiles simply freeze and appear asleep), and inappropriate environments (e.g. reptiles go lethargic in an air-conditioned lab).  The proximate point here is that one should give the lizards a fighting chance by adjusting the test environment to better suit their physiologies and allow them to show their true intelligence.

The ultimate point is to wonder what is intelligence?  Is it a linear, 1D scale of higher hierarchies to lower hierarchies?  Or is it a planar, multi-dimensional geographic distribution of goals and methods?  Two additional sample research studies shed light.

Levinson (1997) compared the spatial encoding among children natively speaking European Dutch vs. Aboriginal Australian Guguu Yimithir.  The task was to recall animal positions in a montage, seen facing north:  Human -> Pig -> Cow.  Recreate this view when turned around and facing south:

·       Dutch: Human <- Pig <- Cow

·       Guguu Yimithir: Cow <- Pig <- Human

The Dutch speakers retained the ego-centric relative positions whereas the Guguu Yimithir speakers retained the absolute third person positions.

Lucy (1992) compared Maya Yucatec toddlers vs. American English toddlers in a classification task.  Select an object that most closely matches a small cardboard box.

·       English: Consistently chose plastic box

·       Yucatec: Consistently chose cardboard sheet

The English speakers were focusing on the shape while the Yucatec speakers were focusing on the materials.

In both cases, the cultural and linguistic differences accounted for the varying outcomes.  To a Dutch speaker from developed world Europe, retaining a hi-fidelity visual image of the scene might aid in describing and sharing it with others.  To a developing world Aborigine living in the arid lands requiring extensive navigational skills to survive, retaining a dynamic directional sense may be more vital.  To an English-speaking toddler, object shape may be more important in stacking, organizing, and arranging toys and books.  To a Yucatec-speaking toddler, focusing on the object materials may be more useful in determining durability and tropical weather life spans.

In both cases, the tests mirror question topics on the standard Stanford-Binet IQ test including memory, spatial orientation, and classification.  In both cases, it is easy to imagine what the linearly 1-D “correct” answer would be and how the Guguu Yimithir and Yucatec speaker could be penalized.  In both cases, it is difficult to reconcile the IQ test mechanism and regional needs for multi-dimensional intelligence. 

IQ tests provide linear, one-dimensional scores.  The history behind the test (Siegler & Alibali, 2005) was intended to detect which students would have a high probability of disrupting the public school classes.  Depending on the parents’ point of view, the public school’s primary or secondary purpose is to socialize the student so as to integrate them effectively into society.  The question that arises is, “Which society?”  IQ tests are undoubtedly very effective in their stated goal of ensuring the students in school are able to keep together and follow their lessons without undue disruption or teacher distraction.  But perhaps that is the same as saying they are effective at ensuring the students in the classes in the society for which they are calibrated all belong to there. 

In a similar vein, perhaps the search for intelligence in “lower order lizards” should not simply be about adjusting the human or mammal intelligence test such that the lizard has a fighting chance at being like a human or mammal, but more about understanding what is intelligence to a lizard.  It should be more about, “intelligence is in the eye of the beholder.”  What is food to a “higher order” primate may be poison to a “lower order” lizard and vice versa. 

This is not simply about human or animal rights.  Whether a person wishes to interview the lizard or wear them as shoes is beyond the scope of this writing.  What is important is the understanding of how we search for intelligence.  To do otherwise limits our tools to merely stating the obvious: a human is more human than a lizard but which is more intelligent is undefined.