Curt Paul Richter (February 20, 1894 – December 21, 1988) was a

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

, psychobiologist and geneticist who made important contributions in the field of

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogeno ...

s. Notably, Richter identified the

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...

as a "biological pacemaker" involved in sleeping and wakefulness. In particular, this region suspected by Richter was later identified as the

suprachiasmatic nucleus The suprachiasmatic nucleus or nuclei (SCN) is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regula ...

. Richter was born on February 20, 1894, in Denver, Colorado to German immigrants. His parents emigrated to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

from Saxony,

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. His father was an engineer who owned a steel and iron firm in Denver. In 1912, he studied engineering at the Technische Hochschule, but left after the outbreak of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

in 1914, switching to

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

where he studied biology under

William E. Castle William Ernest Castle (October 25, 1867 – June 3, 1962) was an early United States, American geneticist. Early years William Ernest Castle was born on a farm in Ohio and took an early interest in natural history. He graduated in 1889 from Deni ...

. Due to his lack of experience with biology, Castle advised that he drop the course and he switched to psychology instead, studying under

E. B. Holt Edwin Bissell Holt (; August 21, 1873 – January 25, 1946) was a professor of philosophy and psychology at Harvard from 1901–1918. From 1926–1936 he was a visiting professor of psychology at Princeton University. Biography Holt was born in ...

and

Robert Yerkes Robert Mearns Yerkes (; May 26, 1876 – February 3, 1956) was an American psychologist, ethologist, eugenicist and primatologist best known for his work in intelligence testing and in the field of comparative psychology. Yerkes was a pioneer ...

. He graduated from Harvard in 1917 and, after a brief tour in the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

, studied under John Watson at

Johns Hopkins University Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hem ...

. Richter induced need states in experimental animals by depriving them of substances essential to survival, or manipulating the hormone levels, and showed that these need states generate appetites, and behaviors precisely fitting the animal's need even if the animal had never before experienced the need; demonstrating genetic programming of behavior. He also triggered other pre-programmed behaviors, such as nest building, by manipulating hormone levels. Richter was elected to the United States

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

in 1948, the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...

in 1956, and the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 1959.

References

External links

''Medical Archives''
* 1894 births 1988 deaths Harvard University alumni Johns Hopkins University alumni {{US-biologist-stub Members of the American Philosophical Society