Saying 'um's' and 'ah's' seems to be something that we all do - even those who don't indulge in changing their neurons through smokables. If, we all, or most of us do it, there must be some evolutionary reason that brings out and justifies the existence of such behavior.
Um, it helps kids learn
“Do you pepper your speech with ‘um’ and ‘uh’?” Parenting asks. “While the habit won’t do you any good in a job interview, it’s a real advantage for teaching your toddler new words. University of Rochester researchers found that when children hear their parents’ stumbles and hesitations (scientific name: disfluencies), it sends a signal that they should pay attention because they’re about to learn something new. ‘A toddler hears a lot of new words when listening to adults, and if his or her brain doesn’t start processing until after the new word is spoken, learning becomes a much more difficult task,’ says Richard Aslin … one of the study’s authors.”
“Do you pepper your speech with ‘um’ and ‘uh’?” Parenting asks. “While the habit won’t do you any good in a job interview, it’s a real advantage for teaching your toddler new words. University of Rochester researchers found that when children hear their parents’ stumbles and hesitations (scientific name: disfluencies), it sends a signal that they should pay attention because they’re about to learn something new. ‘A toddler hears a lot of new words when listening to adults, and if his or her brain doesn’t start processing until after the new word is spoken, learning becomes a much more difficult task,’ says Richard Aslin … one of the study’s authors.”
One issue to explore now is why such behavior is now seen as a sign of non-professionalism or social awkwardness? What historical forces put saying 'um' on the trajectory of impolite behavior?
Another related issue concerns other unprofessional behavior and its social or evolutionary utility. Does or Did faking sick or being tardy have some yet-to-be-seen utility? We can only wait breathlessly for science to deliver the answer.
A Disdain for Silence that Necessitates the Verbalization of Every Moment of One's Thinking + A slow thinking brain that requires time to move to the next word = Unprofessional or Non-Polite Conduct
That Same Disdain + That same Slow-Thinking Brain + Children = Intelligent and Cued in Offspring
