Who is Dr. Philip Zimbardo in the memoir, The Choice?

Dr. Philip Zimbardo is a noted psychologist, professor, researcher, and writer. He is the author of the book's Forward, and introduces Dr. Eger and her work to the reader. He portrays himself as having worked with Dr. Eger, having come to admire her both as a person and as a colleague, and having found significant value in her philosophy and her practice. A key component of the Forward is his consideration of the concept and practice of heroism, which Dr. Eger does not touch on much in the book but which, in Dr. Zimbardo's view, defines her as a person and as a therapist.