Max Hodak Writings

Do we live in the same reality?

July 2020

One of the classic questions of consciousness is whether any two people experience a particular fundamental percept, like the color red, the same way. How can we possibly know whether my red is the same as your red and isn’t instead, say, your green? The answer is we can’t, really, but I don’t want to get too stuck on this because it’s not what this post is actually about; it’s just a jumping off point to highlight the issue that our experiences may be very different in diverse and fundamental ways, and we don’t generally think about this very hard.

We tend to assume that everyone has very similar experience: I think this stems from the deeply held value in our culture that all humans should be thought as as similar, if not equal. This is absolutely the right normative objective, and to the extent it’s not true, it makes sense to me that making it more true should be an important public policy goal. But I’ve been growing increasingly suspicious that our brains, and therefore the nature of our respective realities, are more different than we may have heretofore understood.

Consider two people, one of whom has a perfect photographic memory and another who has a very poor memory. The way they live their lives and experience the world will be very different. Or, one person who is quick to anger and unable to control it versus another who has excellent emotional control and the ability to consider challenging things from a distance. There is no trouble accepting that this variation is present in humans, but there are real questions about how broad the class of these variable qualities is and the impact they have on us.

I’m not asking something like whether biological psychopaths should be criminally responsible for their actions: that kind of normative question is different from what I’m getting at here. The question I am interested in is: to what extent are phenomena like political polarization explainable by differences in cognitive set points? We all know that factory farms are bad, but some people find it so overwhelmingly offensive that they can’t think about other things, while others see it as a problem but one that can be solved by the long arc of history. The difference is not just exposure; there is something else happening here. I doubt we will still be eating animals in a hundred years but I still do it today. Some of my friends cannot imagine it even now. This is not a logic thing, or about hearing the right argument. It is just obviously, deeply wrong to them, and it is ambiently wrong to me.

The goal of language is to take a concept that exists as activity in my brain and recreate it in someone else’s as faithfully as possible. But these differences mean that the reconstruction process is probably much lossier than we assume. This also means that interactive conversation may be more fundamentally different than broadcasting than we’ve understood, since that closed loop feedback is an important error correction mechanism.

I think this is also related to how some people just get art and others find it baffling, or for a more trivial example, how some people love the rain and others find it depressing. On one hand it might seem like what I’m saying is superficial, obvious and pithy. My point is that this is actually very important and fundamental, and we have neglected to explore the impact of these differences.

To tease all this apart, I think the first step is giving up on the notion that the role of the brain is to produce a veridical representation of objective reality. I buy the arguments Donald Hoffman makes for his Interface Theory of perception, and one of the things it tells me is that our relative worlds are probably far more different and far more plastic than we understand. If we have different weightings, and possibly different labelings, our basic perception will reflect that, and since we can’t directly compare between people, we have a hard time realizing it much less quantitating the differences.

It’s important to note that I’m not arguing that this is all due to genetic variation: the brain is a dynamical system that continues adapting throughout life. While some genetically-determined differences may be so dramatic that they are unlikely to be overwhelmed by environment, it’s also probably true that early childhood environment has an enormous impact on everything being discussed here, and it’s further clear that neural networks never stop trying to descend the energy well.

Our brains continue to alter their representations when presented with a new informational environment or a change to the biological substrate, for example due to age, injury, or pharmacological intervention. If they didn’t, we wouldn’t have — for example — drug addiction, basically definitionally. On the other end of the spectrum, experienced meditators show significant differences in brain activity, and meditation is a skill anyone can learn as an adult. To really drive this point home, it is well known that patients who have an electrode placed into their brain can learn to volitionally modulate single neurons almost anywhere in the brain we’ve looked so far, often in as little as a few minutes. Though certain critical periods close, the brain stays surprisingly plastic throughout life.

A successful theory of these differences might yield a quantitative description of the axes of variation at work here, which would give us insight into the structure of the mind. Imagine if you could know for yourself a set of values that when compared to someone else’s, helped facilitate reliably effective information exchange, or I guess in the limit case warned if no useful conversation was possible. The marketing industry has figured out tons of tribal knowledge along a dimension close to this, but that still feels distinct. I suspect deep down this rabbit hole lies a broad theory of human psychology, though it does not feel close at hand.