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Related Experiment Video

Updated: Jun 8, 2026

A Laboratory Method to Measure Contagious Yawning in Rats

A Laboratory Method to Measure Contagious Yawning in Rats

Published on: June 14, 2019

Why do we yawn? Primitive versus derived features.

Andrew C Gallup¹

¹Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. a.c.gallup@gmail.com

Neuroscience and Biobehavioral Reviews

|October 2, 2010

Summary

This summary is machine-generated.

Yawning may serve multiple functions, not just communication. This study critiques the social/communication hypothesis, suggesting a physiological origin for yawning behavior across vertebrates.

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Area of Science:

Ethology
Comparative Psychology
Evolutionary Biology

Background:

Previous reviews suggest yawning lacks a physiological role, favoring a communicative function.
The social/communication hypothesis for yawning is presented as having strong experimental backing.
The evolutionary perspective on yawning is often limited, neglecting comparative and phylogenetic data.

Purpose of the Study:

To critically evaluate the evidence supporting the social/communication hypothesis of yawning.
To address limitations in current research regarding yawning's origin and function.
To propose a multifunctional and evolutionary perspective on yawning behavior.

Main Methods:

Review and critique of existing literature on yawning.
Analysis of evidence for physiological versus social/communicative functions.
Examination of comparative data across vertebrate species.

Main Results:

Lack of definitive experimental support for the social/communication hypothesis.
Insufficient consideration of non-primate comparative data and phylogenetic history.
Evidence suggests yawning is likely multifunctional across species.

Conclusions:

The social/communication hypothesis is an insufficient global explanation for yawning.
A physiological function is the more parsimonious explanation for yawning's origin.
Yawning's social value is likely a derived trait, not its primary evolutionary feature.