Karl Florien Heiser was born in Hamilton, Ohio, on June 30, 1904. His father was Karl William Heiser, who worked as a newspaper writer, a teacher, and later as a florist. His mother was Alta Dell Harvey Heiser, who wrote several books on Ohio history. The Heisers had five sons and were not able to give their son Karl much financial assistance, so the young man worked his way through college with a variety of jobs, including a brief stint selling mortgage stock.

While attending Oberlin College, Karl F. Heiser became interested in psychology due to the influence of Professor R.H. Stetson. He received an A.B. degree in psychology in 1926 and an A.M. in 1927. Three of his brothers followed in his footsteps and attended college at Oberlin: Donald Harvey Heiser (1909-1994, A.B. 1932), Merrill Francis Heiser (b. 1913, A.B. 1934, A.M. 1935), and Will Maynard Heiser (b. 1917, A.B. 1938).

After receiving his A.M., Karl F. Heiser taught for a year (1927-28) at the Hawken School in South Euclid, Ohio. In 1928 he went to Columbia University (N.Y.C.) to pursue graduate studies in psychology, and he earned a Ph.D. in 1932. In the spring of 1929, he met Jennie Vail Byers (b. 1901), and they were married September 3, 1929. They had two children, Karl Robert (b. 1932) and John Vail (b. 1935).

In the fall of 1929, Karl Heiser took a position as an instructor of psychology at Yale University where he taught until 1934. From Yale University he went to the University of Connecticut, Storrs, where he was appointed professor of psychology from 1934 to 1943. Soon after starting the position at Connecticut, he traveled to the USSR. His two months in the Soviet Union dramatically changed his outlook on the world. This experience led him to become involved in activities such as organizing a consumer’s cooperative and opposing compulsory military training. His activism led to tension arising between him and his wife. Jennie wanted Karl to rise in the academic world, a goal that was impossible as long as he was involved in activities, which the university’s senior administration disapproved of. After a series of trial separations during the 1940s, the couple separated for good in 1947, and they were divorced in 1953.

In 1940, Karl started working at the Psychology Laboratories of Norwich (Connecticut) State Hospital; subsequently, he was later named Director, a position he held until 1943. From 1943 to 1945, he was named Director of Research for Connecticut Public Health and Welfare. In 1945, he went to Vienna, Austria, where he worked for two years as a welfare specialist in the Allied Commission for Austria—a Commission consisting of the U.S., United Kingdom, France, and the Soviet Union that worked to solve Austria’s post World War II political and economic problems.

Returning to the United States in 1947, Professor Heiser taught briefly at the University of Michigan, and then in 1948 he took an administrative position with the American Psychological Association. From 1948 to 1951, as the Associate Executive Secretary for the American Psychological Association, he was primarily responsible for evaluating graduate programs in psychology; this position required him to travel extensively in order to visit some seventy schools across the country.

From 1951 to 1954, Karl became the Coordinator of Clinical Services and Research at The Training School in Vineland, New Jersey. His book on mental retardation, Our Backward Children, which was published in 1955, was strongly influenced by his time there.

Karl Heiser met Ruth Bishop in Chicago in 1948 while he was working for the American Psychological Association. Born in Atlanta, Indiana, on June 13, 1909, Ruth Bishop received her B.A. degree from Northwestern University in 1929 and her Ph.D. in psychology from the University of Chicago in 1939. When she and Karl Heiser met, Ruth worked for the Chicago Merit System. In 1949-50, she conducted Veterans Administration student evaluations for the University of Michigan. In 1950 she took a job as Head of Evaluation and Measurement at the National League for Nursing in New York City. She continued in this position until she married Karl Heiser on July 9, 1954.

In 1954, the Heisers moved to Louisville, Kentucky, where Karl took a position with the League for Emotionally Disturbed Children to coordinate efforts to establish a residential treatment facility. A year later, a dispute about the future directorship of the facility led him to resign from the project; following his departure, the treatment center was never completed.

In 1955, the couple moved to New York where Karl Heiser worked for the Psychological Corporation from 1955 to 1956. Ruth Bishop Heiser took a job at Columbia College of Physicians and Surgeons working on a Kellogg Foundation grant to set up standards and evaluate graduate programs in hospital administration. In 1956, the couple decided to go into private practice together as consulting psychologists and moved to Glendale, Ohio, in order to be close to both of their early mothers.

The record suggests that they were the first psychologists in private practice in the Cincinnati area, and Karl and Ruth met a great deal of opposition from psychiatrists. It took a year and a half before they were able to establish a steady practice. To help with expenses during that time, Ruth Bishop commuted to New York to continue her work at Columbia College.

In the late 1960s, Karl Heiser became increasingly active in the Democratic Party. He had concluded that political action was the only way to end the Vietnam War. He ran for the state Board of Education in 1967 and 1969 and ran for a seat in the U.S. Congress from Ohio three times, in 1968, 1970, and 1972.

The Heisers retired in 1974 and moved to Cundy’s Harbor, Maine. Karl Heiser continued to be active in politics, and in 1977 he was elected to the Maine Democratic Central Committee, eventually serving as policy and platform chairman. In 1983 the Heisers moved to Oberlin, where they were active in town affairs and volunteer activities. They were particularly involved in a movement to build a continuing care retirement center in Oberlin, which led to the establishment of Kendal at Oberlin. The Lounge and Auditorium at Kendal were named after the Heisers.

Karl Heiser was an active alumnus of Oberlin College throughout his life. He served as class president 1961-66 and as an officer in numerous regional alumni clubs. He also served as an admissions alumni representative and was involved in several fundraising campaigns for the College over several decades. In 1988 the College named both of them Fellows of the John Frederick Oberlin Society.

Karl Florien Heiser died in Oberlin on July 22, 1991 from complications following heart surgery. Ruth Bishop Heiser died six days later, on July 28, 1991; she had progressive lung disease.