- 1896 – Lev Vygotsky, Belarusian-Russian psychologist and philosopher (d. 1934).
- 2014 – Patrick Suppes, American psychologist and philosopher (b. 1922).
Lev Semyonovich Vygotsky (Russian: Лев Семёнович Выго́тский; Belarusian: Леў Сямёнавіч Выго́цкі; 17 November 1896 to 11 June 1934) was a Soviet psychologist, known for his work on psychological development in children. He published on a diverse range of subjects, and from multiple views as his perspective changed over the years. Among his students was Alexander Luria and Kharkiv school of psychology.
He is known for his concept of the zone of proximal development (ZPD): the distance between what a student (apprentice, new employee, etc.) can do on their own, and what they can accomplish with the support of someone more knowledgeable about the activity. Vygotsky saw the ZPD as a measure of skills that are in the process of maturing, as supplement to measures of development that only look at a learner’s independent ability.
Also influential are his works on the relationship between language and thought, the development of language, and a general theory of development through actions and relationships in a socio-cultural environment. This can be found in many of his essays.
Patrick Colonel Suppes (17 March 1922 to 17 November 2014) was an American philosopher who made significant contributions to philosophy of science, the theory of measurement, the foundations of quantum mechanics, decision theory, psychology and educational technology. He was the Lucie Stern Professor of Philosophy Emeritus at Stanford University and until January 2010 was the Director of the Education Program for Gifted Youth also at Stanford.