Recognizing patterns and applying them in new situations may be two key features of
language and thought, but what happens when the pattern's wrong?
Last time I pulled out a critter you'd never seen before, a shwuff, and I think we agreed
that we'd immediately know what to say if I had 5 or 6 of them.
But that's not thanks to the shwuff so much as it is to our understanding of plurals.
There's a paradigm for plurals in English, and it works for words big and small, short
and long.
So we have reason to be pretty confident that this is just how plurals work in English.
Then, eventually, we run into some word that doesn't fit the paradigm.
We've abstracted and analogized this general idea about plurals, but its inadequacy is
staring us in the face.
This roadblock is not just a problem for the grammar of English plurals.
If you ever had to fight your way through some basic logic before, you noticed that
we use general statements about "all this" or "every that" to draw conclusions.
But just like with "mice" and "alumni", we're always at risk of running smack into something
that doesn't fit with the general statement we've worked so hard to abstract and apply
by analogy.
If you were living in the 1700s and your name were David Hume, you would've pushed this
point very hard, wondering "why from this experience we form any conclusion beyond those
past instances, of which we have had experience".
This gets called the "problem of induction", and it asks us frankly why we should have
predicted that the plural of "mouse" would be "mouses" just because the plurals of other
words ended in -s.
Of course, if I'm learning English, this seems like a fairly trivial event.
I note the exception, I hope that I remember it next time and I move on.
But not all failed applications of paradigms are this mundane.
Nassim Nicholas Taleb uses the metaphor of the "black swan" - swans are white, not black,
or so Europeans thought until British ornithologist John Latham stumbled across real life black
swans in Australia.
The black swan has since become a mascot for rare events that have a surprisingly huge
impact, yet aren't accounted for in the "normal" paradigm.
These abnormalities strike us as obvious AFTER the fact, just as obvious as it is to an English
speaker that "mice" is the plural of "mouse" and to modern avian enthusiasts that not all
swans are white.
We can of course incorporate this new information, and maybe even be a little smarter with our
paradigm by hedging against big unknowns.
But...
can we go the other way?
Let's turn to plurals just one more time.
A child might get corrected for saying "mouses", sure, and they might step in line.
But at some point English-speaking children applied this same paradigm incorrectly, and
instead of incorporating the correction, they grew up to overturn the old norms.
Sometimes we simplify, other times we preserve the irregularity.
And there's even room for creativity as brand new patterns emerge.
As we learn about language and thought, and use thought and language to learn, exceptions
to the rule give us very useful feedback about the patterns we think we see.