Origin of "noogie"?

As far as I know, “noogie” has two meanings:

  1. In the dismissal “tough noogies,” meaning something like, “you’ll take it and you’ll like it;” and
  2. that thing you do either playfully or, if you’re stronger want it to burn, less playfully, by rubbing your knuckles briskly over someone’s scalp.

Anyone know the etymology of either of these two meanings?

The Oxford English Dictionary only discusses your meaning (2). It says that the origin and etymology are unknown, but that it was popularized by Saturday Night Live in the late 1970’s. The first appearance they list is in 1968.

The OED also notes a different definition of `noogie’: “J. E. Lighter Hist. Dict. Amer. Slang cites a New York University student in 1972 as saying that a ‘noogie is a kind of a punch or a jab you give someone with your third and middle finger. You do it on the forehead or on the shoulder.’”