The Jaffe Memo table lists William Shockley’s speech in Ontario, in 1967, as a source for ideas. The same speech is cited by Bernard Berelson, in his article Beyond Family Planning, which must in some way be a reaction to Jaffe’s memorandum. Here is the reference as provided by Berelson:
As of this writing, the New York Post article itself hasn’t been found, but presumably is derived from an AP article, reproduced below. Several other news articles reflecting the same speech are listed below. The three versions provide a good picture of the content of Shockley’s remarks.