Definition
Symbolic thinking is the capacity to let one thing stand for another — a word for an object, a flag for a nation, a gesture for an idea. It is among the defining features of the human mind and the foundation of language, metaphor, religion, and culture.
Behave treats this ability as a double-edged gift. The same machinery that makes meaning possible also lets abstractions trigger emotions and actions as powerfully as real things do.
Why it matters
How it works
The brain does not keep symbols neatly quarantined from the things they represent. Behave describes how the regions that process physical experience are reused for metaphorical ones — a literally dirty act and a morally "dirty" one engage overlapping circuitry, and a literally warm room and a "warm" person can color each other's perception.
This blurring is why symbols move people so forcefully. An insult to a flag is processed almost as an insult to the nation; a sacred value resists being traded away the way a sacred object resists being sold. The upside is that symbolic thinking makes abstract ethics possible at all. The downside is that a metaphor calling a group "vermin" can do the work of real contempt — meaning is powerful precisely because the brain treats it as more than mere words.