Hearing, understanding and IQ

Many years ago I returned to college from my grandmother's funeral.  On the trip back, my appendix acted up.  I got back to my dorm, dropped my stuff and headed straight on over to the hospital where they diagnosed acute appendicitis and whipped that thing right out of there.  

I was in a hospital room for a couple of days after that, a room which I shared with a pleasant gentleman.  Possibly Cornelius might have been his name.  Cornelius was in for some foot surgery.  He worked as a janitor.  As pleasant as he was, he was also very low in intelligence, a fact which kept getting him into trouble.  He would get out of bed and wander around despite his bandaged up foot.  He would want more pain reliever than was authorized.  He accidentally pulled down the venetian blinds at the window.

None of it was malicious.  Nor, really, even deliberate.  He just got himself into trouble a lot, mostly because he didn't understand the world around him.

He was perhaps the first person whom I got to know to a degree to understand just what an impediment it is to have a very low IQ.  

One of the moments of realization occurred one afternoon.  

A couple of friends from college had come over to visit with me.  They sat on either side of the bed, a three way conversation, with me turning from one to the other as they spoke.  Cornelius on the other side of the room watching.

While we were talking, my phone rang.  I excused myself from the conversation and picked up the receiver.  Whoever it was, it was a three or four minute conversation.  I hung up and returned to talking with my friends.  I had tracked what they were talking about as I spoke on the phone and so just slid right back into the conversation.

A little later, they left and it was just Cornelius and me in the room.

Cornelius turned to me and said 

"How did you do that?"  

"What?"

"You were talking on the phone and listening to your friends at the same time."

Of course I had not thought about that as a capability and it was Cornelius who made me aware of just how much we take for granted.  For me it was just an ordinary thing.  For Cornelius, it was a capability beyond imagination, to follow two conversations at the same time.  

Nearly five decades later, I come across recent research bearing upon Cornelius's observation.

From IQ Linked to How Well You Hear in a Crowd.  

“We found a highly significant relationship between directly assessed intellectual ability and multitalker speech perception,” the researchers reported. “Intellectual ability was significantly correlated with speech perception thresholds in all three groups.” 

A lot of brain processing contributes to successful listening in complex environments, Lau said.  

“You have to segregate the streams of speech. You have to figure out and selectively attend to the person that you’re interested in, and part of that is suppressing the competing noise characteristics. Then you have to comprehend from a linguistic standpoint, coding each phoneme, discerning syllables and words. There are semantic and social skills, too — we’re smiling, we’re nodding. All these factors increase the cognitive load of communicating when it is noisy.”