I’ve sometimes seen/heard the phrase “mouth-breather” used for a stupid or crude person. Why?
Previous threads on the question:
Wait a minute, “mouth breathers” ?
Why Is Mouthbreathing Associated With Stupidity?
The many syndromes that are associated with impaired cognitive function include many which comprise developmental failures during the period of fetal development that includes the formation of the forebrain, and the sensory cluster in the face. That includes the period when the sinuses and nasal passages develop. Cleft palates, deviated septums (septa?), and other sorts of aberrant development of the upper respiratory tract are non-causal co developments in many of the syndromes that affect intelligence.
It happens to also be true that many neural development deficits include a general low level of muscle tone, including the muscles of the face. The dynamics of cognitive development are strongly affected by both of these factors as well. So, the conjoining of the symptoms of low intelligence and mouth breathing has an actual component of observable accuracy. Since visual assessment of personality by observation of facial expression an extremely primitive level of social interaction, it has been reinforced by thousands of generations of human social development. Those of us who could voluntarily do so found that keeping our mouths shut improved our perceived social standing.
The existence of the associative relationship is logically non compelling, but that never changed all that many minds. Some people who are unintelligent keep their mouths open all the time, therefore being a mouth breather means you, and your opinions can be dismissed without consideration.
You want to hear about drooling morons?
Tris