- 1896 – David Wechsler, Romanian-American psychologist and author (d. 1981).
- 1914 – Mieko Kamiya, Japanese psychiatrist and psychologist (d. 1979).
- 1941 – Fiona Caldicott, English psychiatrist and psychotherapist.
David Wechsler (12 January 1896 to 02 May 1981) was a Romanian-American psychologist. He developed well-known intelligence scales, such as the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC).
Wechsler is best known for his intelligence tests. He was one of the most influential advocates of the role of non-intellective factors in testing. He emphasized that factors other than intellectual ability are involved in intelligent behaviour. Wechsler objected to the single score offered by the 1937 Binet scale. Although his test did not directly measure non-intellective factors, it took these factors into careful account in its underlying theory. The Wechsler Adult Intelligence Scale (WAIS) was developed first in 1939 and then called the Wechsler-Bellevue Intelligence Test. From these he derived the Wechsler Intelligence Scale for Children (WISC) in 1949 and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) in 1967. Wechsler originally created these tests to find out more about his patients at the Bellevue clinic and he found the then-current Binet IQ test unsatisfactory. The tests are still based on his philosophy that intelligence is “the global capacity to act purposefully, to think rationally, and to deal effectively with [one’s] environment”.
The Wechsler scales introduced many novel concepts and breakthroughs to the intelligence testing movement. First, he did away with the quotient scores of older intelligence tests (the Q in “I.Q.”). Instead, he assigned an arbitrary value of 100 to the mean intelligence and added or subtracted another 15 points for each standard deviation above or below the mean the subject was. While not rejecting the concept of general intelligence (as conceptualized by his teacher Charles Spearman), he divided the concept of intelligence into two main areas: verbal and performance (non-verbal) scales, each evaluated with different subtests.
A Review of General Psychology survey, published in 2002, ranked Wechsler as the 51st most cited psychologist of the 20th century.
Mieko Kamiya (神谷 美恵子, Kamiya Mieko, 12 January 1914 to 22 October 1979) was a Japanese psychiatrist who treated leprosy patients at Nagashima Aiseien Sanatorium.
She was known for translating books on philosophy. She worked as a medical doctor in the Department of Psychiatry at Tokyo University following World War II. She was said to have greatly helped the Ministry of Education and the General Headquarters, where the Supreme Commander of the Allied Powers stayed, in her role as an English-speaking secretary, and served as an adviser to Empress Michiko. She wrote many books as a highly educated, multi-lingual person; one of her books, titled On the Meaning of Life (Ikigai Ni Tsuite in Japanese), based on her experiences with leprosy patients, attracted many readers.
Dame Fiona Caldicott, DBE, FMedSci (12 January 1941 to 15 February 2021) was a British psychiatrist and psychotherapist who also served as Principal of Somerville College, Oxford. She was the National Data Guardian for Health and Social Care in England until her death.