&gt; <i>There are multiple hypothesis of what a sequence of words can mean, which is not the same thing as &#x27;we form explicit syntax trees in our heads when reading a sentence&#x27;.</i><p>Yeah. I&#x27;m playing with a different idea now - maybe that &quot;tree structure&quot; that &quot;undeniably exists&quot; in our brains isn&#x27;t an explicit syntax tree, but an artifact of recursive, adaptive pattern-matching? I.e. if you look at things like reading speed or &quot;understanding&quot; speed, you&#x27;ll notice that people tend to process stuff in large blocks until something &quot;does not click&quot;, and they have to focus and process the block in detail. That sort of feels like a recursive refinement, and any process that recurses in more than one place generates a tree structure as a side effect.