Ethel May Nicholson, his maternal grandmother, had raised him as her son from his birth. She had maintained this identity for his entire childhood and young adulthood. She had died in 1970. She had not told him.
Lorraine, June’s sister, had been the final living family member who knew. She confirmed the truth when Jack reached out after the Time researcher’s call.
What could not be definitively established, and remains uncertain:
The identity of Jack Nicholson’s biological father. Donald Furcillo, who married June in 1936 and died in 1997, claimed paternity. Patrick McGilligan’s biographical research identified Eddie King — Edgar A. Kirschfeld — as another possibility. June herself may have been uncertain. No genetic testing has been publicly confirmed. The paternity question remains, as of the available public record, unresolved.
Why the arrangement was made in the specific form it was. The historical context — the social stigma attached to unmarried pregnancy in late 1930s Catholic New Jersey, the available legal frameworks for managing such situations, the pressures on a young woman who had been pursuing an entertainment career — provides the landscape in which the decision was made. But the specific conversations, the specific reasoning, the specific agreements between June and Ethel May, are not in the public record.
What June experienced, across twenty-six years of watching her biological son grow up as her brother. She gave no interviews about this. She wrote no memoir. She is represented in the available record primarily by what other people said about her and what the external facts of her life contained: the stage name, the entertainment career, the marriage to Furcillo, the death in 1963.