Grover Cleveland “Cleve” Backster, Jr. was born on February 27, 1924 in LaFayette, New Jersey to G.C. Backster and Nina L. Backster, and graduated from Franklin and Marshall Academy (Lancaster, Pennsylvania) in 1941.

In January 1943, Backster enlisted in the Navy and was honorably released to inactive duty on 4 July 1946. He was awarded a World War II Victory Medal. It appears that he then moved to the Los Angeles area of California, operated a body building gym, and used the alias of William "Bill" Baxter.

In March 1947, Backster re-enlisted, this time with the Army Counter Intelligence Corps, where he became involved in criminal investigation and counterintelligence techniques in his role as CIC Investigator at Fort Holabird, Maryland. He was honorably discharged in April 1948, whereupon he spent two years at the CIA and became an interrogation specialist. In 1949 he instituted the CIA's polygraph examination program.

Throughout 1951-1952, Backster periodically was employed by the Army to attend training and to work as a Expert (WAE) in the Armed Forces Security Agency (AFSA). In 1951 he also founded Cleve Backster Inc. as owner and operator of the Backster School for Lie Detection. Backster also worked for commercial polygraph consulting companies, including the National Training Center for Lie Detection (1959-1962). In 1962, he refocused his professional work on The Backster School of Lie Detection with the purpose to research and and to train law enforcement in techniques of interrogation using a polygraph. His Backster Zone Comparison Technique is still in use today.

In 1964, Backster was part of a group to test whether the ninhydrin fingerprint method was viable in determining if people claiming to be Grand Duchess Anastasia of Russia matched prints from copybooks retained by the Duchess' childhood tutor.

Backster testified before the Foreign Operations and Government Information Subcommittee of the U.S. House of Representatives about polygraph testing in 1964 and in 1974.

In 1965, he created the Backster Research Foundation, Inc.

In 1966, Backster connected his polygraph electrodes to a dracaena plant to see how it would respond to various stimuli. He reported that the polygraph showed a “stress response” the moment he thought about harming the plant, as if the plant could read thoughts and emotions. Another more objective test showed the plant would respond when brine shrimp were killed in the same room. He tested this response in further experiments with plants, yogurt, eggs, and other cells, and reported that they all had the capacity to respond to other living systems. He called this phenomenon “primary perception,” believing that this type of biocommunication was a universal capacity of life. He explained his decades of research in his 2003 book Primary Perception: Biocommunication with Plants, Living Foods, and Human Cells.

Although other scientists struggled to replicate what became known as the “Backster effect” (except for Marcel Vogel, who reported a successful replication), Backster stood by his results and maintained that other researchers were not preparing their experimental systems correctly: they were not doing all that was necessary to “eliminate human consciousness” from their laboratory setting. He traveled and lectured extensively about his research, advocating for a paradigm change to consciousness research that opens to the possible effect of the experimenter’s intent.

He died on June 24, 2013 in San Diego, CA after a prolonged illness.