Theory falsification

Question: if you want to falsify a theory, do you need a plausible alternative theory?

Toy-examples of falsification suggest not, but I think they mislead. For example: my theory is “there is a fairy in my cupboard”. Potentially falsificatory test of this theory: open cupboard – is there a fairy there? Ignoring for the moment the problem of the impossibility of hard falsification, it looks fairly straight forward. That was the theory, there was the test.

However, this toy example is so simple it allows us to leave implicit the plausible alternative, namely there is no fairy in the cupboard. If no plausible alternative is to hand, I don’t think identifying a potentially falsifying test is so straightforward.

I arrived at this train of thought via a discussion last night about vegetarianism. I was trying to convince people that we have have an evolved disposition to obsess about and ritualise our food behaviours, so that any food habit, however arbitrary or initially unideologically – for example not eating meat just because you happen to live with vegetarians – can quickly and easily embed itself in our psychological preferences and become the subject of purity rituals and taboos (“Don’t cook my vegeburger in your bacon fat!” sort of thing).

I’ve been trying to think of a way to test/falsify this theory and can’t. This either means that the information content of the theory is actually minimal – i.e. it isn’t actually saying anything – or it means (my best guess for the truth) that my scientific imagination isn’t very good. And I think the missing link in my chain of thought it the lack of any apparent plausible alternative. Simple negating the theory (“food behaviours are not subject to purity obsessive behaviour”) doesn’t produce an interesting theory, and the tests that it suggests would, i feel, be passed without actually providing evidence that my theory is any good at all, just better than nothing. In other words, I think I would find people are obsessive about food behaviours, some of which are pretty arbitrary, but I don’t think this would allow me to convince anyone that what I am saying is true.

The problem may be with the nature of the theory (an evolutionary ‘just so’ story?) rather than with falsficiation.

5 replies on “Theory falsification”

The two theories are very different beasts. The fairy in the cupboard hypothesis is a simple statement of fact about the current state of affairs, so it can be falsified (or verified) by just checking the facts. Your other example is much more complicated. For starters, just the premise that we have a disposition to do something is a very subtle idea and probably meaningless without further explanation. Presumably you mean that some of the causes of our doing these things are internal or intrinsic to our situation rather than external or accidental. None of these are straightforward ideas. Then you suppose that this state of affairs has evolved, which is a statement about our history – how we got to be this way rather than how we currently are. And you probably have ideas about why evolution followed this path, which brings in causes. So your theory is a complex, rather vague, ill-defined collection of varied statements about a huge swathe of psychological and historical events. No wonder it’s hard to falsify!

Would your theory of ‘obsessive vegetarianism’ be disproved if you could verify a stronger/different hypothesis? What if people start as ‘just’ obsessive about not eating food cooked in the fat from another animal, but later became concerned about the livelihood of that animal/their health? If you could verify this theory of ‘conversion vegetarianism’, then your original theory would be the trivial one, as a subpart of the stronger theory.
If people came to believe something that wasn’t working on the same ‘just so’ story level of evolution (I am leaving room for another evolutionary story about vegetarianism), then the explanation of maintaining food rituals and of inheriting food behaviours is weakened.

So more generally, my assertion is that a theory can be falsified by (a) verifying the negation of the theory or (b) verifying a stronger theory. Of course, you are still left with the difficult of proving there are no fairies in your cupboard. This is the same problem as has maintained theology departments for hundreds of years. Can you prove God does not exist?

Peter – yes, i think this is key: the wider explanatory context defines how you make sense of your theory (and any tests of your theory)

On reflection, the vegetarianism thing probably isn’t the best vehicle for exploring this one (although it happened to be the prompt for me thinking of it).

On theory testing: I think, now, perhaps you can falsify a theory even if you don’t have any plausible alternative theories. What you are left with, to the extent that you falsify your sole original theory, is a lack of explanations – i.e. a mystery – and that’s a legitimate scientific state of affairs (albeit an undesirable one).

On vegetarianism: Yes, it’s a myriad of vague and ill-defined ideas, but most interesting theories in psychology will be. Questions we could ask: do people generally adjust their beliefs to fit their behaviours (in all domains, not just food)? Do they do more so with food? Are ‘obsessive’ food behaviours universal (cross cultures, cross individuals)? Is this trend from behaviour to ideology actually followed by individuals who adopt food practices (such as vegetarianism)? Is the direction of people’s ritualisation arbitary, or does it follow a particular course (although i’m not sure what this would show exactly, either way)? The possibilities for testing the theory seem richer to me now than on saturday night…

I think falsifiability is not a very useful criterion in the social sciences. It shouldn’t be too difficult too “prove” that your theory about vegetarianism is “false” since it would be enough to find one vegetarian who would not “ritualize” his gastronomical behaviour – and as a matter of fact you’d be a very good candidate for that part ! 😉 We all know however that you have hit on something that experience shows is true.

Note that you also have a problem of logic here, since every human feeding behaviour, which consists of choosing certain foods and discarding others, can be analyzed as a “ritual”. If the extension of the concept “ritual” becomes too important, your question becomes a tautology.

Leave a Reply

Your email address will not be published. Required fields are marked *