The Return of Karl Popper: Is Social Science Really Different Than Natural Science?

karl-popper Social Scientist have contended for much of the last century that we cannot approach the study of human behavior with the same tools that we would use to study the natural world.  This is hogwash.  And Karl Popper, the great 20th century philosopher, would agree with me. Humans are animals, they are made up of chemicals and cells, their behavior is determined by a complex interaction of chemical processes and their lives are a network of cause and effect relations with other animals (some of which we’d call human).   If we are ever going to get a solid grasp on our own behavior, we’ll need to use the items from the large and well developed toolbox of natural science.

Falsifiability and Objective Reality

Karl Popper believed that a theory is scientific if and only if it is falsifiable.  Most scientists would agree with this statement, and in fact would be shocked by anyone who didn’t.  (This may be why natural scientists and social scientists don’t tend to hang out together!)  But, falsifiability presupposes a belief in an Enlightenment-style “objective” reality beyond that of our own minds.  In much of social science, especially in sociology and psychology, there is a powerful belief in a post-modern relativism that rejects an objective reality. That is to say, they don’t believe that there is a truth that is inherent to the objects of study themselves.

Without a belief in an objective truth outside the mind of the observer, it is impossible to even discuss what it would mean to falsify a statement.  Therefore, you cannot use Poppers falsifiability axiom as a demarcation line for what is and isn’t science.  And now we allow in all sorts of unfalsifiable statements and theories simply because who is to say what is and is not objectively true?  This is not good science.  But, it defines much of what passes for science in the world of social inquiry.

Now, it must be said, that the truth is likely somewhere in the middle. But, most relativists are basing their relativism on what I’d consider a false understanding of some basic ideas.  Among the more common things I hear when encountering someone who is a hardcore relativist, who wants to impress me (knowing that I’m a mathematician) is with the idea of quantum physics.  It usually goes something like this, “hey, man, you know that every time we observe a particle we change it’s state.  So, everything is relative.  Our presence changes what we observe.  There is a reflexivity between us and the object.  There is no way to know what’s what if every time observe something that something changes.  Reality can be and is manipulated.”

OK, true.  But, it’s missing the point.  When we say we change a particles state, we aren’t saying the particle didn’t have a state to begin with.  It was simply a state we can’t directly observe.  That isn’t relativism in the strictest sense.  Sure if I observe it and you observe it, we’ll see different things, but that doesn’t mean the particle didn’t have an objective state before we each changed it. True relativism would be that the particle has no state until someone observes it. But, that isn’t how it is.

Octavian-coin Think of a particle as a coin.  Suppose I spin that coin on a table.  While it is spinning is it heads or tails?  You might say neither, or more accurately, you could say both.  It’s 50% heads and 50% tails.  That’s it’s objective state.  The trouble is, suppose we can’t see a coin spinning.  Suppose we can only see coins when they are heads or tails with 100% probability – that is, when they are flat on the table.  Then if I want to observe the coin, I have to slam my hand down on top of it to stop it from spinning.   Say it lands heads up.

When I leave, suppose it pops back up and begins spinning again.  Then you come by and slam your hand down on it.  Now it’s landed on tails.  We’ve each seen the same coin in different states.  I claim the coin is heads, you claim the coin is tails, but neither of us realizes that it is both.

Many things in the natural world are of this form.  That doesn’t mean we can’t study them objectively, and infer what we can, correct for our own “observation” errors, etc.  Physics is going just fine with far crazier objects than humans could ever hope to be.  There is no reason we have to pretend that studying human behavior is somehow so much harder than studying particle physics.

Popper’s 3 Worlds

There is no doubt that the reality outside our minds is not always in line with the perceived reality we hold within our minds.  Many natural scientists, in light of this, are Cartesian dualists without even knowing it.  That is, they accept that there are two worlds: the world of material things that we study; and the world of the human mind. They accept that these don’t always jive, and that each one has an influence on the other.  But, keeping them separate, at least heuristically, is seen as useful.

In social science there is a stronger emphasis on the effects culture on the mind.  And this is seen as a feedback loop from the mind to itself.

Karl Popper goes one step further with his heuristic and suggests that the universe is really made up of three worlds.  The objective world of objects.  The world of the Mind.  And the world of human-created ideas as manifested in books, paintings, blogs, etc.   The third world includes culture and so brings it out of the second world, thus striping it of some of its recursive properties.

What I like about the idea of the third world is that it allows for this world to undergo it’s own evolution (the way the other two obviously do).  And because of this we can study it (largely) independently using the tools of evolutionary research such as game theory.

One More Time

I contend that Social Science is a proper subset of Natural Science and is in fact a subset of Biology, most specifically Human Biology.   To say that we cannot study Social Science with the same tools we use in Natural Science because we are ourselves of the type we are studying is an act in strange logic. If we follow the strange logic further, then we shouldn’t study any animals like we study the natural world, because we are animals.  We shouldn’t study chemistry as we study the natural world because we are made up of molecules.  And we shouldn’t study physics the way we study the natural world because we are nothing more than a collection of atoms.

There is always some sense of recursion in any attempt we make to study the natural world.  Our brain is made up of cells which use electricity to fire information back and forth.  Whenever we are trying to understand electricity, we are using electricity to understand it!

Popper dealt with this problem in what I consider a most reasonable way, the Popeye way:  Science is what it is, and that’s all that it is.  Scientific statements can only be falsified, not verified.   And the world (including the world of human interaction) has an objective component that must be sought after as truth in its own right.  It isn’t perfect, but it gets the job done.

The only way we’ll ever make headway into the realm of human behavior is if we are comfortable approaching the human animal the way we approach the study of all animals – with science.

14 responses to “The Return of Karl Popper: Is Social Science Really Different Than Natural Science?

  1. Pingback: Natural vs Social Science: Karl Popper | Math for Primates

  2. Quantum physics (as I understand it) states that a thing does not exist until it is observed.
    Two questions:
    What is a thing? Our brain divides reality into any number of “things.” Such divisions, though, say more about the limits of cognition than they do about reality.
    Also, when is something observed? When light reflected from a thing strikes the lens of our eye? The retina? The visual cortex? When the processed image is bound into consciousness?
    As irrational as it might sound, I believe one must understand reality to be capable of understanding reality.

  3. You said,”Quantum physics (as I understand it) states that a thing does not exist until it is observed.”

    That isn’t correct. If it was, then the universe would not have existed before humans did, because we would not have been around to observe it. This would have caused us to never have existed in the first place. A paradox.

    Quantum particles do certainly exist whether we observe them or not. The question is what happens to them once they are observed.

    You’re right, though, that defining “observe” is no small matter. In fact, another question one might ask is is it fair to say that only humans have the ability to observe something, or do animals have that ability also?

    I don’t have any answers on how we should define ‘observe’. Good topic!

    • First thanks for writing this. It eloquently says a lot of what I think. I was going to write about this very subject on my own blog, but now I can just link to yours.

      I’m very interested though in what it means to observe something from a quantum physics perspective. It’s certainly still an open question in physics. As I understand it, observing the state of something at the quantum level “collapses the wave function” of the object you’re observing, which can mean many different things depending on which flavor of quantum physics you choose. In the copenhagen interpretation (which is usually what the relativists base their thinking on), your observation “forces” the particle into one state or another by mysterious means. In many worlds, by contrast, observation does nothing to the quantum system, and simply answers the question of which of the multitude of universes the observer is in.

      The key point though, regardless of which interpretation you choose (excepting some of the extremely new agey ones) is that is is not the state of your mind regarding the object which affects it, but your interaction with it. And you can observe something without interacting with it, so observation affects quantum systems. A human observer isn’t required, nor even is a living one; simply taking a measurement with any tool could do it (again, unless you’re very new agey, in which case you might say nothing happens until you look at the measurement).

      Of course, I’m just looking at this from a layman’s perspective. There’s too much scientific uncertainty, and far too much math, for me to say for sure that I know what I’m talking about.

      • sorry, that should be “you can’t observe something without interacting with it”

        There’s also been some interesting work done in the last year in doing just that, probing a quantum system without affecting it, but I can’t find the link at the moment.

      • Actually I think you’re hitting the nail on the head. There ARE lots of different interpretations. And some of them are voiced by guys going fist to fist at one another!

        You’re right, it isn’t your state of mind affecting the particles, it’s your actions.

        Since I’m a mathematician, I tend to stick largely on the mathy side of things. That is, I think of quantum systems as being embedded in Hilbert spaces and I use linear algebra to describe everything.

        This is no doubt convenient, and has proven highly useful in practical experiments by physicists … but, it is itself just an interpretation (like all math is) of the real world that we can’t really see or observe the way we’d like to.

        I’ve got my own conceptions, but I could easily be wrong.

  4. Pingback: The Return of Karl Popper: Is Social Science Really Different Than … | Drakz Free Online Service

  5. wilderness voice

    >falsifiability presupposes a belief in an Enlightenment-style “objective” reality beyond that of our own minds.

    Not so. This is clearly inadequate when considering the validity of a mathematical theorem, for example. Falsifiability requires merely that an assertion is capable of being demonstrated to be false in the minds of observers who understand the subject at hand.

    • I mostly would agree with your take on this. But, I’m still inclined to disagree officially. 🙂

      Here’s why. Let’s take mathematical theorems. Mathematicians, as a group, are Platonists. That is, they (even if only subconsiously) believe that there are higher “forms” that are the pure objects (like spheres) and then the universe is filled with crude versions of these things (like the earth).

      Theorems are, according to most mathematicians, either true or not, regardless of what other people believe about them. And our job as a mathematicians is to discover the most elegant way to prove that it is true or prove that it is false. But regardless of our efforts, the fact of the theorem being true or false already exists independently of us.

      The proof itself is the convincing tool we use on ourselves and on our colleagues. But, the fact that it was true or not existed before we attempted to prove it. Ut had an objective (inherent) quality independent of my own interpretation or presentation of proof.

      • wilderness voice

        >the fact of the theorem being true or false already exists independently

        I agree with this. But in practice the only method of making this determination is via intersubjective evaluation by unbiased and educated observers. I agree that this same rigor should be applied to other sciences where the results are not readable on, say, a voltmeter. By the same token, for example, lack of said voltmeter may not be used to dismiss verifed reports of patients unconscious on the operating table witnessing events out of sight and earshot.

      • Very true. And in fact, I’m uncomfortable with much of the Platonic view points. I can’t prove them to be false (pun intended), but they don’t sit right with me.

        I’d be happier saying that there are no ideal forms out there in the “ether”. That what we see is what we get. But, then I’d have to give up on the idea of a theorem having an inherent truth value. Instead, all that would matter would be if we can prove it in a manner that a majority of “experts” can agree with.

        This would make mathematics far more of a subjective field.

        It’s easy to see how this has been such a conundrum for nearly all of human philosophical history!

  6. The first commenter was correct – individual particles DO NOT have a definite quantum state when they are not being observed – that is the whole point of QM. It does not mean that “the universe wouldn’t have existed” before humans, because the universe is not a single quantum particle – it is a macroscopic system and we know from experience that macroscopic systems do not require quantum treatment. Somewhere between a few atoms and a few thousand atoms, we can stop treating systems quantum mechanically – basically when the energy of the system is substantially greater than the energy of whatever we would need to probe that system with in order to observe it. But when dealing with INDIVIDUAL PARTICLES, when there is nothing “smaller than” those particles with which to interact with and observe them – it is ABSOLUTELY NECESSARY to say that they DO NOT exist in any single well-defined state when not being observed. At least, this is the interpretation of the vast majority of physicists.

    • (Actually reading the first commenter more closely – it’s not that QM claims particles do not EXIST when not being observed, it’s that we can not attribute a definite state to those particles – a precise position, energy, momentum, etc – until we observe it. It is this precise quantum state which can be said not to exist – not the particle itself.)

      • I think we need to make sure we aren’t talking past one another. The problem is the word “state” itself.

        In our normal language the word state means something totally different than it does in quantum mechanics.

        Going back to the coin example: From our perspective a coin can have only 2 reasonable, or in your words, clear “states”, Heads or Tails. But, in a quantum mechanical world, that isn’t the case. It in fact has a continuum of possible states.

        Let p be a number between 0 and 1. If we let the state of our coin (particle) be s=pH + (1-p)T, then the coin is indeed in state “s”.

        It’s just not a state that we’re going to be able to observe. All we see is a probabilistic equation telling us the likelihood of whether, when we DO observe it, it will come up heads or tails.

        But, that isn’t any less a state. And in the world of quantum mechanics, that is in fact the definition of a “quantum state”: a mathematical object that describes the quantum system we’re trying to understand.

        We call H and T the basis states or basis vectors of our 2 dimensional space. And we take convex linear combination’s of those basis vectors. Each possible combination is yet another possible state.

        What is confusing is that this doesn’t jive with our intuitive definition of “state”.

        In the normal definition we’d use in the “real” world, the coin is either heads OR tails with 100% probability. And any other probability is just a prediction tool we use to guess whether it will land heads or tails.

        Like, 1/3H + 2/3T tells us that we have a higher likely hood of landing tails. But, in quantum mechanics that would be the state itself.

        It’s just a matter of semantics. In quantum mechanics, the probability equation IS the state. They use a different definition entirely. No doubt this is one of the many reasons the field is so confusing.

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