Ever wonder who's to blame for AIR QUOTES, you can apparently blame STEVE MARTIN. According to MentalFloss.com, Steve is the one who "popularized" air quotes during his standup and "Saturday Night Live" appearances back in the day.
Steve even gets a shout-out on the Wikipedia page for "air quotes". It seems like the first place Steve got credit for air quotes was a book called "How We Got Here: The '70s, The Decade that Brought You Modern Life, for Better or Worse". It says, quote, "Martin taught a whole generation of young people the distant, cool, ironic sensibility summed up by the gesture he popularized . . . the four-fingered drawing of double-quote marks in the air."