biology

Nathaniel Kleitman

Nathaniel Kleitman is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nathaniel Kleitman rather than just read about it. In short: Nathaniel Kleitman (April 26, 1895 – August 13, 1999) was an American physiologist and sleep researcher who served as Professor Emeritus in Physiology at the University of Chicago. He is recognized as the father of modern sleep research, and is the author of the seminal 1939 book Sleep and Wakefulness.

Key takeaways

Nathaniel Kleitman belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nathaniel Kleitman to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nathaniel Kleitman from memory before moving on to harder problems.

Reference excerpt

Nathaniel Kleitman (April 26, 1895 – August 13, 1999) was an American physiologist and sleep researcher who served as Professor Emeritus in Physiology at the University of Chicago. He is recognized as the father of modern sleep research, and is the author of the seminal 1939 book Sleep and Wakefulness.

Biography

Early life Nathaniel Kleitman was born in Chișinău, also known as Kishinev, the capital of the province of Bessarabia (Moldova), in 1895 to a Jewish family. He was deeply interested in consciousness and reasoned that he could get insight in consciousness by studying the unconsciousness of sleep. Pogroms drove him to Palestine, and in 1915 he emigrated to the United States as a result of World War I. At the age of twenty, he landed in New York City penniless; in 1923, at age twenty-eight, he had worked his way through City College of New York and earned a PhD from the University of Chicago's Department of Physiology. His thesis was "Studies on the physiology of sleep." Soon after, in 1925, he joined the faculty there. An early sponsor of Kleitman's sleep research was the Wander AG company, which manufactured Ovaltine and hoped to promote it as a remedy for insomnia.

REM sleep Eugene Aserinsky, one of Kleitman's graduate students, decided to hook sleepers up to an early version of an electroencephalogram machine, which scribbled across 1⁄2 mile (800 m) of paper each night. In the process, Aserinsky noticed that several times each night the sleepers went through periods when their eyes darted wildly back and forth. Kleitman insisted that the experiment be repeated yet again, this time on his daughter, Esther. In 1953, he and Aserinsky introduced the world to "rapid-eye movement," or REM sleep. Kleitman and Aserinsky demonstrated that REM sleep was correlated with dreaming and brain activity. Another of Kleitman's graduate students, William C. Dement, who was a professor of psychiatry at the Stanford medical school, described this as the year that "the study of sleep became a true scientific field."

Rest activity cycle Kleitman made countless additional contributions to the field of sleep research and was especially interested in "rest-activity" cycles, leading to many fundamental findings on circadian and ultradian rhythms. Kleitman proposed the existence of a Basic rest activity cycle, or BRAC, during both sleep and wakefulness.

Other experiments Kleitman also conducted sleep studies underground in Mammoth Cave, Kentucky and lesser-known studies underwater in submarines during World War II and above the Arctic Circle.

Worked examples

Example 1 — a first encounter with Nathaniel Kleitman

Start with the simplest possible case. Write down what Nathaniel Kleitman claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nathaniel Kleitman before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nathaniel Kleitman ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nathaniel Kleitman

In research: Nathaniel Kleitman appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nathaniel Kleitman in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nathaniel Kleitman is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1895 births, 1999 deaths, American men centenarians, so understanding it makes those chapters shorter.
In everyday life: Look for Nathaniel Kleitman outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nathaniel Kleitman in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nathaniel Kleitman means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nathaniel Kleitman out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nathaniel Kleitman in simple terms?

Why does Nathaniel Kleitman matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nathaniel Kleitman?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nathaniel Kleitman.