How is this different than saying asians are smarter than black people?
Does it mean ALL people that listen to instrumental only are smarter or that switching to instrumental only makes you smarter? No it doesn’t.
Just like not all Asians are smart or all black people are athletic.
“Does it mean ALL people that listen to instrumental only are smarter or that switching to instrumental only makes you smarter?”
Actually, you can gain a full 10 IQ points if you listen to at least 4 hours of banjo instrumentals a day.