Dialogue of the deaf

I had a stimulating discussion with a neuroscientist the other day. I tried to explain to her that my interest in children’s cognitive development is linked to my interest in epistemology, that is, to what I refer to in this blog as the normativity of thought.

For example, I argue that researchers who try to explain children’s knowledge of math from a nativist point of view, can only explain the starting point of cognitive development. The starting point is innate mathematical knowledge, which is mostly implicit, and basically consists in an ability to identify the numerosity of collections of objects found in the outside world. In other words: researchers have shown that animals (humans included) have the innate ability to assess the size of a collection of perceived objects (for example, they can notice that a collection of 15 pebbles is greater than a collection of 10 pebbles). They can also discriminate among exact quantities, but only when dealing with small sets (two, three, and perhaps four objects). Also, some animals and human babies can perform elementary arithmetic operations on small sets (adding two plus one, subtracting one from two, etc.) I am referring here to studies by Dehaene (2011), Izard, Sann, Spelke, & Streri (2009), Spelke (2011), and many others.

This basic capacity is certainly different from fully-fledged “human math.” The latter involves, at the very least, the symbolic representation of exact numbers larger than three. We (humans) can represent an exact number by saying its name (“nine”), or by using a gesture that stands for the number in question (depending on the culture, this might be done by touching a part of one’s body, showing a number of fingers, etc. – see Saxe ( 1991) and also http://en.wikipedia.org/wiki/Chinese_number_gestures). And, of course, we can write down a sign that represents the number (for example, with using the Arabic numeral “9”).

Scholars agree on the fact that advanced math is explicit and symbolic, and that it builds on (and uses similar brain areas to) its precursor, innate math. Once they operate on the symbolic level, humans can do things like: performing operations (addition, subtraction, multiplication, division, and others), demonstrating mathematical propositions, proving that one particular solution to a mathematical problem is the correct one, etc. To sum up: our symbolic capacities allow us to re-describe our intuitive approach to math on a precise, normative, epistemic level.

Now, here’s when it gets tricky. I argue that the application of algorithms on the symbolic level is not merely mechanical. Humans are not computers applying rules from a rule book, one after the other (like Searle in his Chinese room). Rather, as Dehaene (2011) argues, numbers mean something for us. “Nine” means nine of something (anything). “Nine plus one” means performing the action of adding one more unit to the set of nine units. There is a core of meaning in innate math; and this core is expanded and refined in our more advanced, symbolic math.

When executing mathematical operations (either in a purely mental fashion, or supported by objects) one gets a feeling of satisfaction when one arrives to a right (fair, correct, just) result. Notice the normative language we apply here (fair, correct, right, true, just). We actually experience something similar to a sense of justice when both sides of an equation are equal, or when we arrive to a result that is necessarily correct. (Note to myself: talk to Mariano S. We might perhaps do brain fMRIs and study if the areas of the brain that get activated by the “sense of justice” in legal situations, also light up when the “sense of justice” is reached by finding the right responses in math. If a similar region gets activated, that might suggest that there is a normative aspect to math that corresponds to the normative aspect of morality).

For me, then, the million dollar question is: how do humans go from the implicit, non-symbolic, automatic level to the explicit, symbolic, intentional and normative level? What is involved in this transition? What kind of biological processes, social experiences and individual constructions are necessary to achieve the “higher,” explicit level? (These are interesting questions both for the field of math and for the field of morality). And my hypothesis is that this transition necessarily demands the intervention of a particular type of social experience, namely, the experience of the normative world of social exchanges and rules of ownership (I’ve talked a little about such reckless hypotheses in other posts of this blog).

Now, when I try to explain all this to the neuroscientist, I lose her. She doesn’t follow me. For her, human knowledge is the sum of a) innate knowledge and b) learning from the environment. Learning is the process by which our brain acquires new information from the world, information that was not pre-wired, that didn’t came ready to use “out of the box.” Whether such learning involves a direct exposure to certain stimuli that represent contents (a school teacher teaching math to his or her students) or a more indirect process of exposure to social interactions is not an interesting question for her. It doesn’t change her basic view according to which there are two things, and two things only: innate knowledge and acquired knowledge. What we know is the result of combining the two. And this is the case both for humans and for other animals. Period.

Something similar happens when I talk to her about the difference between “cold processing” and “hot processing.” We were discussing the research I am conducting right now. I interview children about ownership and stealing. In my interview design, children watch a movie where one character steals a bar of chocolate from another, and eats it. The interviewer then asks the child a series of questions aimed at understanding her reasoning about ownership and theft. Now, the movie presents a third person situation. This means that the child might be interested in the movie, but he or she is not really affected by it. Children reason about what they see in the movie, and sometimes they seem to say what they think it’s the appropriate thing to say, echoing adults’ discourse. Because, after all, the movie is fiction, not the real world.

I believe that normativity emerges not from absorbing social information that comes from external events (watching movies, attending to teachers’ explanations) but from children’s real immersion in first person, real world, conflictive situations. When a child is fighting against another for the possession of a toy, there are cries and sometimes there even is physical violence. These encounters end up in different ways; sometimes children work out a rule for sharing the scarce resource, sometimes they just fight, and sometimes an adult intervenes and adjudicates in the conflict. The child’s reactions during these events is not dictated by cold reasoning but by deeper impulses. It is in these situations where we should look for the emergence of our basic normative categories, such as reciprocity (both social and logical, or “reversibility”), ownership (or the relationship between substance and its “properties”), quantity (used to implement equity and equality), etc.

But, again, my biologist friend does not feel that the distinction between the impulsive, intense, hot reactions we experience when involved in real conflicts and the kind of third person reasoning that is triggered by movies and artificial stimuli is an important one. In both cases, she argues, it’s the same cognitive system that is at work. What we think about third person characters is probably similar to how we reason about ourselves (thanks to our capacity for empathy, our mirror-neurons, etc.)

I don’t know who’s right and who’s wrong here.

 

Dehaene, S. (2011). The Number Sense: How the Mind Creates Mathematics, Revised and Updated Edition. The number sense How the mind creates mathematics rev and updated ed (p. 352). Oxford University Press, USA. Retrieved from http://www.amazon.com/dp/0199753873

Izard, V., Sann, C., Spelke, E. S., & Streri, A. (2009). Newborn infants perceive abstract numbers. Proceedings of the National Academy of Science, 106(25), 10382–10385.

Saxe, G. B. (1991). Culture and Cognitive Development: Studies in Mathematical Understanding. Hillsdale: Lawrence Erlbaum Associates.

Spelke, E. S. (2011). Quinian bootstrapping or Fodorian combination? Core and constructed knowledge of number. Behavioral and Brain Sciences, 34(3), 149–150.