MLA Format

Advance Access Publication 16 January 2006 eCAM 2006;3(1)61–63

doi:10.1093/ecam/nek015

Review

Humor and Laughter may Influence Health. I. History and Background

Mary Payne Bennett1 and Cecile A. Lengacher2

1Indiana State University College of Nursing, IN, USA and 2University of South Florida College of Nursing, FL, USA

Articles in both the lay and professional literature have extolled the virtues of humor, many giving the

impression that the health benefits of humor are well documented by the scientific and medical commun-

ity. The concept that humor or laughter can be therapeutic goes back to biblical times and this belief has

received varying levels of support from the scientific community at different points in its history.

Current research indicates that using humor is well accepted by the public and is frequently used as a

coping mechanism. However, the scientific evidence of the benefits of using humor on various health

related outcomes still leaves many questions unanswered.

Keywords: Humor – Health

Can Humor and Laughter Influence Health Outcomes?

History

Using humor to decrease stress, diminish pain, improve quality

of life and even attempt to improve immune functioning has

recently become a popular topic in the lay and professional

literature (1–4). Laughter in response to a humorous stimulus

is a natural occurrence and does not require large amounts of

time or money in order to implement. While therapies such

as relaxation and exercise require significant time and commit-

ment, and therapies such as herbs or massage can be expen-

sive, use of humor can be easily implemented and cost

effective. However, clinical benefits must still be documented

before this therapy can be widely supported by the health care

community.

Diverse literature suggests that effects of humor on various

outcomes such as stress, health and immune function have

been well-documented by empirical research and are therefore

commonly accepted. The work of Cousins (5), Fry (6–11),

Berk (12–17) or the field of Psychoneuroimmunology (PNI)

is frequently cited as supporting the role of humor in healing.

However, despite media claims, relatively few professional

articles examine the scientific basis for these claims. There

are a few studies that have examined the effects of humor or

laughter on psychological outcomes, such as stress. However,

there are a very limited number of studies that document

the effects of laughter on physiological outcomes, and no

controlled studies have been identified that document the

effects of laughter on clinical health outcomes.

So what do we really know about the role of sense of humor,

use of humor by patients with various illnesses, or the effects

of laughter on various health related outcomes? Is use of

humor an approach that we should implement in our practices

and/or recommend to our patients? This is the first of the four

articles that reviews, clarifies and synthesizes the professional

literature concerning humor and health outcomes. This first

paper presents basic background on the theoretical under-

pinnings concerning how the mind can affect the body, such

as the effects of stress on immune functioning. Research in

this area provides fundamental support for the supposition

that interventions that lower stress may also help improve

physiological outcomes. The second paper reports studies

that document patient interest in and use of humor as a com-

plementary therapy, and provides evidence to support that

humor may be one of the more frequently used complement-

ary therapies. The third paper describes studies that report

For reprints and all correspondence: Mary Payne Bennett, Indiana State University College of Nursing, IN, USA. Tel: 1-812-237-2320; Fax: 1-812-237-8895; E-mail: mbennett2@isugw.indstate.edu

� The Author (2006). Published by Oxford University Press. All rights reserved.

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the relationship between sense of humor and various health

outcomes. The final paper examines either the effect of a

humorous stimulus and/or effects of laughter on health out-

comes. These latter two parameters are difficult to separate,

since patients who are exposed to a humorous stimulus usually

respond with laughter, however, not all studies separately

document laughter and exposure to a humorous stimulus.

This review is based on a search of Pub-Med and

PsychINFO, using the search terms humor and laughter,

plus bibliographic review for older articles that may not be

documented in the databases. A search using those terms pro-

duced 324 hits, from which 55 relevant articles were obtained.

Only original empirical research reporting the psychological or

physiological effects of humor or laughter are reported here,

with the main focus on research documenting health related

outcomes. Owing to small sample sizes in most studies and

the limited number of available reviews, sample size was not

used as a determinant to exclude certain analyses from our

review. A meta-analysis was not possible owing to the use

of multiple measures of sense of humor and various outcomes

utilized in the studies reviewed.

Definitions

A full discourse on humor theory is beyond the scope of this

review, but certain basic definitions are essential. From a psy-

chological perspective, humor involves cognitive, emotional,

behavioral, psycho-physiological and social aspects (18). The

term humor can refer to a stimulus, which is intended to pro-

duce a humorous response (such as a humorous video), a men-

tal process (perception of amusing incongruities) or a response

(laughter, exhilaration). Laughter is the most common expres-

sion of humorous experience. Humor and laughter are also

typically associated with a pleasant emotional state (18). For

the purpose of these reviews, humor is defined as a stimulus

that helps people laugh and feel happy. Laughter is a psycho-

physiological response to humor that involves both character-

istic physiological reactions and positive psychological shifts.

Sense of humor is a psychological trait that varies considerably

and allows persons to respond to different types of humorous

stimuli. It is necessary to differentiate between these variables,

as some analyses of humor use a humor stimulus (such as a

video) to determine the effect of ‘humor’ on an outcome, while

others look specifically at the effects of laughter on these out-

comes. Still others analyze various ways to measure sense of

humor, in an attempt to determine whether scoring higher on

a sense of humor instrument is related to various health related

outcomes.

Stress, Psychoneuroimmunological Reactions and Health

Theoretical Framework and Early Experiments

What is the underlying theoretical framework that helps

explain why use of a complementary therapy, such as humor,

may affect health? It may be that these therapies work by

reducing the effects of stress. Interest in the influence of

psychological factors on susceptibility to certain disease states

goes back to the times of Galen (19), when it was noted that

persons who developed cancer often had a ‘melancholic’

personality. Since then, numerous clinicians have shared

anecdotal data concerning the development of cancer or other

diseases in persons with certain psychological styles, or after

a stressful life event, such as bereavement (20).

Selye’s work was one of the first to document the general

effects of stress on the sympathetic nervous system, endocrine

system and lymphatic organs (21). Further studies established

that activation of the stress response could also be triggered

by acute emotions, physical exertion, cold and pain (22). Later,

Lazarus and Folkman (23) broadened the definition of stress

from Selye’s concept of ‘environmental demands’ to include

psychological components such as appraisal and coping.

While Lazarus and Folkman’s theory helped to explain the

moderation of stressors using coping mechanisms, it did not

attempt to explain the possible consequences of these coping

mechanisms in terms of physiological effects on immune func-

tioning. The field of PNI brings all of these factors together in

a testable theoretical framework. PNI started from a multi-

factorial model of illness, which included stress, coping and

disease formation (24). This theory was further developed

by Solomon (1987) to include the impact of stress on the

immune system in disease formation (25). Later, the term

‘psychoneuroimmunology’ was coined by Ader and Cohen

(26) to describe the basic phenomena of this theory: interac-

tions between the nervous system and the immune system,

and the subsequent effects of these…