QBism and Subjective Experience


Text Analysis: “A Private View of Quantum Reality” by Amanda Gefter in Quanta Magazine

Relevance to Schools & Ecosystems: Connects to our prior analysis of schema and the limitations in human perception

In our last post (an analysis of Richard Nisbett’s article, “The Bugs in Our Minds“) we discussed how our perceptions of reality are heavily subjective, based on mental models called schemas, and all too readily misled by stereotypes or heuristics triggered by seemingly inconsequential factors.

There’s an interesting parallel here to a theory of quantum mechanics from Christopher Fuchs called QBism. QBism challenges the notion of an “objective reality,” suggesting instead that reality lies in the eye of the beholder.

The Collapse of a Wave Function Lies in the Eye of the Beholder

By BrentHFoster (Own work) [CC BY-SA 4.0], via Wikimedia Commons
In terms of quantum theory, QBism interprets a “wave function’s probabilities as Bayesian probabilities — that is, as subjective degrees of belief about the system.” The act of perceiving is thus akin to that of gambling. “The wave function’s “collapse” is simply the observer updating his or her beliefs after making a measurement.”

We assess and predict each event based upon prior events, and thus our understanding of probability, as suggested by Nisbett’s article, can be easily misled by the “representativeness heuristic”: that events are judged as more likely to occur if they are similar to prior types of events: think of the gambler’s “hot hand.”

As we gain more information, we can update our “bets,” or our schemas, to better reflect that information. But we’re still making a grand bet against the wider chaos of the unknown. Fuchs describes the situation as thus:

“Since the wavefunction doesn’t belong to the system itself, each observer has her own. My wavefunction doesn’t have to align with yours. . . .

Quantum mechanics is not about how the world is without us; instead it’s precisely about us in the world. The subject matter of the theory is not the world or us but us-within-the-world, the interface between the two.”

I wonder, then, if we can hedge our bets when we make a greater effort to understand the subjective experiences of others, as well as the us-within-the-world?

Hedging Our Bets by Assuming Responsibility

What I like about the perspective of QBism is that probability is framed “as a description of uncertainty and ignorance,” rather than as objective certainty. This certainly aligns with our lived experience. Our frail, emotional human existence, defined by our feeble daily fumblings to communicate, can more accurately be described as shots in the dark, rather than that of rational actors responding to and acting upon objective information. While that sounds like a belittling of the human experience, in other ways it is empowering: it means that the greatest of power lies within:

“Usually we think of the universe as this rigid thing that can’t be changed. Instead, methodologically we should assume just the opposite: that the universe is before us so that we can shape it, that it can be changed, and that it will push back on us. We’ll understand our limits by noticing how much it pushes back on us. . . . 

Now there’s a spectrum of positions you could take. . . . there’s no reason whatsoever for my probabilities and yours to match, because mine are based on my experience and yours are based on your experience. The best we can do, in that case, if we think of probabilities as gambling attitudes, is try to make all of our personal gambling attitudes internally consistent. I should do that with mine, and you with yours, but that’s the best we can do. . . .

The best you can do is gamble on the consequences of your actions.”

In other words, be true to your subjective experience and understanding of the world, and take ownership of the actions you take—because just as you are shaped by the world, you too are shaping it likewise within each moment that you exist. There’s poetry here:

“. . . the stuff of the world is in the character of what each of us encounters every living moment — stuff that is neither inside nor outside, but prior to the very notion of a cut between the two at all.

If you have it in your heart — and not everyone does — that the real message of quantum mechanics is that the world is loose at the joints, that there really is contingency in the world, that there really can be novelty in the world, then the world is about possibilities all the time, and quantum mechanics ties them together.”

We are the Happenstance Music Makers of our Universe

This touches on a strange dichotomy in our human experience: we are on the one hand mere products of chance and fortune, while on the other hand, we are the music makers, and we are the dreamers of dreams. We would do well, then, to heed Nisbett’s advice on how to mitigate the errors in our perspectives.

Gefter, A. (2015, June 4). A Private View of Quantum Reality | Quanta Magazine. Retrieved June 29, 2015, from https://www.quantamagazine.org/20150604-quantum-bayesianism-qbism/

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