plural psychologies
1
: the science of mind and behavior
studied psychology in college
2
a
: the mental or behavioral characteristics of an individual or group
the psychology of athletes
We need to understand the psychologies of the two people involved in the incident.
Which fear is more likely to rule the day has to do with each person's psychology and perception of risk.Hannah Herrera Greenspan
b
: the study of mind and behavior in relation to a particular field of knowledge or activity
the psychology of learning
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.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
From behaviorism to cognition During much of the first half of the 20th century, behaviorism strongly influenced American psychology. Encyclopedia Britannica, 8 Sep. 2026 No book has done more to pose uncomfortable questions about the psychology and ethics of reporting in war zones than Michael Herr’s 1967 Dispatches, his account of reporting on the Vietnam War. Nick Holdstock, The Dial, 8 Sep. 2026 In making these distinctive name choices, automakers are tapping into human psychology. Usa Today, USA Today, 7 Sep. 2026 The bottom line, however, is that psychiatry and psychology should not compete over markers. Torie Bosch, STAT, 5 Sep. 2026 See All Example Sentences for psychology

Word History

Etymology

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

First Known Use

1749, in the meaning defined at sense 1

Time Traveler
The first known use of psychology was in 1749

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Cite this Entry

“Psychology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/psychology. Accessed 13 Sep. 2026.

Kids Definition

psychology

noun
plural psychologies
1
: the science or study of mind and behavior
2
: the particular ways in which an individual or group thinks or behaves
Etymology

from scientific Latin psychologia "the study of the mind and behavior," derived from Greek psychē "soul, mind" and Greek -logia "science, study"

Medical Definition

psychology

noun
plural psychologies
1
: the science of mind and behavior
2
a
: 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
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