The Zeigarnik effect, imperfect verbs, and Laser Pointer Syndrome
Is the ability to track unfinished tasks an innate human capability or is it learned?
In searching for the data structures of natural intelligence there’s an unresolved elephant in the room; the instinct to seek completion. It’s the stuff of legend, felt so deeply that it’s used as an explanation for why the dead might come back to haunt us. It seems to be nearly as deeply engrained in humans as the ability to learn causal relationships. It influences our memory (the Zeigarnik effect) and is baked into our grammar.
Spanish verb tenses
I’ve been slowly improving my Spanish over the years. It seems I never have the time or tenacity to devote the majority of my time to it for months, so instead I have little weekend or week long bursts of studiousness every couple years.
During my most recent burst, I was relearning the difference between the Perfect and Imperfect.1 As an English speaker, the difference between past, present, and future tense is immediately obvious. But the difference between Perfect and Imperfect is more subtle. They modify and muddy the temporal aspect of a tense.
Perfect indicates the action indicated by the verb has a definite end. Imperfect casts uncertainty as to whether the action has a definite end.
To give an English example, let’s conjugate the phrase “I speak”. The Present Perfect would be “I have spoken”, and the Past/Present Imperfect would be “I was speaking”. In saying “I have spoken” the speaker indicates the action is complete. We don’t know precisely when it completed, but it is definitely no longer happening. Whereas saying “I was speaking” indicates the speaker hasn’t necessarily finished. The passive aggressive retort to being interrupted is “I was saying something” not “I have said something”.
It is fascinating to me that keeping a to do list in our heads is such a fundamental human experience that it is baked into our languages. Was there ever a time before humans tracked unfinished tasks? Is this an invention passed down through language, or is language reflecting something we’ve always done?
Animals tracking unfinished tasks
Did you know cats aren’t the only animals that chase laser pointers? Some dogs do as well. But it can trigger Laser Pointer Syndrome in dogs, which is described as similar to OCD. Why and how does it create a problem? The theory is that it triggers dogs’ prey instinct, but without the satisfaction of catching the prey. So they end up frustrated and anxious, chasing something that can’t be caught. In support of this theory, the recommended therapy is to encourage the dog to chase physical objects that it can catch and chew on, to help it have more satisfactory experiences.
This anecdote suggests that tracking incompleteness is not uniquely human. Perhaps it’s something shared by all predatory animals? It’s entirely possible that the prey instinct is separate from the completion instinct, but we’d need some examples of completion-seeking behavior in non-predatory animals to provide more clarity.
But for the purpose of deciding which came first, the ability to track incompleteness for the language verb tense, this example in dogs is compelling evidence that humans were keeping to do lists in their heads before language was invented.
Data structures of natural intelligence
With that, I’d like to log some data structures that appear to be innate in human intelligence (as well as the intelligence of some other animals):
Discretization
Directional invariant relationships (causality)
Setting goals
Tracking incompleteness
Detecting uncertainty
Common artificial data structures
In contrast, here are some data structures that are so common in modern society that they seem innate, but are in fact learned:
Language
Numbers
So, precisely how is incompleteness tracked in the human brain? What structures are involved, and how does it fit into the algorithm of natural intelligence? Needless to say, these questions will be living rent free in my head until I find a satisfactory answer…