Heywood was born in Gibraltar, the daughter of Coote Hedley and his wife Anna, and attended the University of London. In 1938, Heywood joined the Society for Psychical Research. She is most well known for her book The Sixth Sense and her autobiography, The Infinite Hive. Heywood would later become the Vice-President of the SPR. The psychical researcherRenée Haynes wrote that her books have "illuminated the subject matter of parapsychology for thousands of readers inside the Society and beyond." It was alleged that Heywood experienced cases of extrasensory perception. She also wrote on paranormal topics. In her book The Sixth Sense Heywood endorsed the cross-correspondences, ESP experiments, mediumship and psychic phenomena. In a review, psychologist E. F. O'Doherty wrote that the clairvoyant cases that Heywood supported such as the psychic Stefan Ossowiecki were not scientific and chance guessing may explain some of the data that she believed was evidence for ESP. Psychologist C. E. M. Hansel wrote that the book is superficial, uncritical and the experiments are no longer taken seriously by the majority of parapsychologists. Heywood described the case of Ossowiecki who had guessed the contents of a sealed envelope in 1933, Hansel wrote that the conditions of the experiment were reminiscent of a simple conjuring trick. Ralph W. Gerard gave the book a positive review but stated the results from the experiments may be explainable by alternative factors such as misinterpretation or unintended cues without recourse to the paranormal. In the New Scientist, John Cohen wrote that although Heywood was "entirely convinced" from the results of card-guessing experiments "Heywood fails to detect the vulnerability of these studies... she has failed to see the shortcomings of the experimental procedure itself." Cohen wrote the objection to Heywood's psychical claims is that no adequate evidence had been presented. Heywood was a friend of Beverley Nichols, he interviewed her for his book Powers that Be.
Publications
Telepathy and Allied Phenomena: With a Section on Quantitative Experiments by S. G. Soal
