Your guess is as good as mine here. This phrase appears in Wikipedia but the citation in the article only supports the stuff in the quotation marks, not the phr

Your guess is as good as mine here. This phrase appears in Wikipedia but the citation in the article only supports the stuff in the quotation marks, not the phrase "master race": > Maslow studied what he called the master race of people such as Albert Einstein, Jane Addams, Eleanor Roosevelt, and Frederick Douglass rather than mentally ill or neurotic people, writing that "the study of crippled, stunted, immature, and unhealthy specimens can yield only a cripple psychology and a cripple philosophy."[11]: 236 > … > Maslow, A (1954). Motivation and personality. New York, NY: Harper. ISBN 978-0-06-041987-5. I took a read through the text in question ( https://archive.org/details/motivationperson00masl_0 https://archive.org/details/motivationperson00masl_0 ) and while the quoted text seems to have been quoted accurately, the phrase "master race" doesn't appear in that book. What Maslow seems to be saying in that section (from an extremely quick skim) is that he is talking about the Seven Habits of Highly Effective People, although he uses the phrase "healthy people" to refer to the people he's writing about.