psy·​chol·​o·​gy | \ sī-ˈkä-lə-jē How to pronounce psychology (audio) \
plural psychologies

Definition of psychology

1 : the science of mind and behavior
2a : the mental or behavioral characteristics of an individual or group
b : the study of mind and behavior in relation to a particular field of knowledge or activity
3 : a theory or system of psychology Freudian psychology the psychology of Jung

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The Roots of Psychology

The word psychology was formed by combining the Greek psychē (meaning “breath, principle of life, life, soul,”) with –logia (which comes from the Greek logos, meaning “speech, word, reason”). An early use appears in Nicholas Culpeper’s mid-17th century translation of Simeon Partliz’s A New Method of Physick, in which it is stated that “Psychologie is the knowledg of the Soul.” Today, psychology is concerned with the science or study of the mind and behavior. Many branches of psychology are differentiated by the specific field to which they belong, such as animal psychology, child psychology, and sports psychology.

Examples of psychology in a Sentence

She studied psychology in college. the psychology of an athlete the psychology of crowd behavior We need to understand the psychologies of the two people involved in the incident.
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Recent Examples on the Web The Purple and Red Rooms contain titles on history, health, politics, religion, games, business, psychology, languages, travel and more. oregonlive, "Powell’s will reopen more rooms to the public at its flagship City of Books store downtown," 25 Feb. 2021 Even in fields like psychology, where women make up the majority of students in undergraduate and graduate programs, men held two-thirds of full professorships as of 2014. Grace Huckins, Wired, "As More Women Enter Science, It’s Time to Redefine Mentorship," 11 Feb. 2021 Something else has also changed: the psychology of the patients, specifically, baby boomers. John Hanc, Star Tribune, "Need a new knee or hip? A robot may help install it," 21 Jan. 2021 If this is the end, the double major at Stanford (psychology, sociology) will have options. Eric Branch,, "2 Super Bowl rings, 0 snaps: 49ers’ Tyler Gaffney aims to finally realize NFL dream," 31 Dec. 2020 But unlike psychology, in which researchers have tried to replicate famous studies and failed in about half the cases, ecology has no smoking gun. Cathleen O’grady, Science | AAAS, "Psychology’s replication crisis inspires ecologists to push for more reliable research," 9 Dec. 2020 The feedback draws on psychology, nutrition, and exercise physiology. Stefani Sassos, Ms, Rdn, Cso, Good Housekeeping, "What Is the Noom Diet? A Nutritionist Explains How the App Can Help You Lose Weight," 12 Nov. 2020 Researchers from Stanford University, Princeton University, the University of Washington, and other institutions partook in an online conference last week by Stanford about the confluence of A.I., psychology, and neuroscience. Jonathan Vanian, Fortune, "Inside Waymo’s autonomous trucks and A.I. systems," 13 Oct. 2020 The Vaccine Confidence Project, which began in 2010, comprises more than a dozen staff with backgrounds in political science, psychology, mathematical modeling, epidemiology and more. Jenny Anderson, New York Times, "She Hunts Viral Rumors About Real Viruses," 13 Oct. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'psychology.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of psychology

1749, in the meaning defined at sense 1

History and Etymology for psychology

New Latin psychologia, from psych- + -logia -logy

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Learn More about psychology

Time Traveler for psychology

Time Traveler

The first known use of psychology was in 1749

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Statistics for psychology

Last Updated

3 Mar 2021

Cite this Entry

“Psychology.” Dictionary, Merriam-Webster, Accessed 7 Mar. 2021.

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More Definitions for psychology



English Language Learners Definition of psychology

: the science or study of the mind and behavior
: the way a person or group thinks


psy·​chol·​o·​gy | \ sī-ˈkä-lə-jē How to pronounce psychology (audio) \

Kids Definition of psychology

: the science that studies the mind and behavior


psy·​chol·​o·​gy | \ -jē How to pronounce psychology (audio) \
plural psychologies

Medical Definition of psychology

1 : the science of mind and behavior
2a : the mental or behavioral characteristics typical of an individual or group or a particular form of behavior mob psychology the psychology of arson
b : the study of mind and behavior in relation to a particular field of knowledge or activity color psychology the psychology of learning
3 : a treatise on or a school, system, or branch of psychology

More from Merriam-Webster on psychology

Nglish: Translation of psychology for Spanish Speakers

Britannica English: Translation of psychology for Arabic Speakers

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