Dr. Gregg was an interesting guy. For 20 years he was the chief of the medical sciences division of the Rockefeller Foundation and he retired as vice president of the foundation.
He was the guy who approved a grant for Alfred Kinsey, which helped him found the the Institute for Research in Sex, Gender and Reproduction at Indiana University, and a few years later Gregg would approve a grant to Duke University for research in Parapsychology under the direction of J. B. Rhine.
He must have been a pretty courageous and independent thinker to be willing to fund such controversial research. Dr. Warren Weaver was at the Rockefeller Foundation at the time and he supported the grant to the lab, but a Dr. Mark S. Morison did not (apparently quite strenuously).
The Rockefeller Foundation terminated the Lab’s grant in 1954 alas, the same year they terminated their grant to Kinsey.