Gargan stopped short of explaining why we've forgotten how to laugh.
Shortly after the birth of TV, which brought us many of the great laugh shows, like "Fibber McGee and Molly" and "Amos 'N' Andy," the networks decided it was too hazardous financially to put on comedy shows and pray for a positive audience response. So, in strategic seats in the audience, they placed "yakkers"--professional laughers--who would respond to appropriate lines with thunderous claps of laughter. Often, the job was done by the writers, but I know of many yakkers who were paid.
Then along came the laugh tracks--prerecorded audience responses that were categorized as No. 1, for a small laugh, all the way up to No. 4, for a belly whopper. These same recordings were used time and again on various shows, and, as Fred Allen once observed, "many of the laughs are coming from people long since dead."
The spontaneous initiative of the audience to laugh was removed, and they simply became robots responding to professional responders.
DAVID R. SCHWARTZ