Cette thèse originale,
plus anthropologique que neuropsychologique,
se propose de replacer le bâillement dans
le scénario de l'évolution, tant
du point de vue de sa physiologie, que dans sa
fonction de communication. Après un
parcours taxinomique fouillé, E Schniter
explore les liens qui peuvent se tisser entre
fréquence et type de bâillements en
fonction de l'âge, des hormones et
d'agents pharmacologiques, de l'environnement,
etc, au sein de multiples espèces de
primates. Il passe en revue les études
sur le bâillement chez l'homme et semble
attacher une grande importance aux
théories de Nolman (parues dans Paradigm
avril 1998) sur l'impact du bâillement
dans la circulation du liquide
céphalo-rachidien, mais non disponibles
dans les revues médicales.
Son apport personnel est une tentative
d'exploration de la contagiosité du
bâillement, en affinant les
méthodes antérieurement
utilisées par R.Provine (dont la critique
parait bien sévère et
déplacée): dosage de la
testostérone salivaire des sujets
étudiés, stimulus par des acteurs
en situation de comportement de
supériorité, ou de soumission,
comparaison avec une mire colorée,
enregistrement vidéos des sujets au lieu
de leur propre témoignage...Tout ceci
afin d'avoir une comparaison possible avec
l'étude des comportements de
bâillements des primates. L'importance de
l'échantillon de sujets
étudiés, 110 étudiants de
son université, parait ambitieuse.
Hélas, la multiplicité des
variables prises en compte réduit la
pertinence des conclusions qui me sont apparues
bien confuses. Vu la rareté des
études sur le bâillement, il faut
néanmoins saluer l'effort
méritoire fourni pour mener à bien
un tel travail.
Résumé : Though common
across the animal kingdom, little is known about
why we yawn, and even less about why yawning is
contagious in humans. By means of literature
review and laboratory based study, this thesis
investigates why we yawn and under what
circumstances observation of yawns elicits a
contagious response. Previous studies have
failed to investigate effects of dominance, sex,
and hormones on yawning contagion.
Research suggests that yawning helps
facilitate transitions between activities.
Costly signaling theory suggests that because
yawns signal anticipated change in activity,
they impose a certain "cost" by revealing
critical information about the yawner;
therefore, dominance factors, sex, and hormones
should all affect the frequency of contagious
yawns.
The experiment sampled subjects' salivary
testosterone and recorded their reactions to
short videos featuring various yawn stimuli, in
an effort to understand better the evolution of
an apparently widespread feature of social
signaling, controlled subconsciously by social
and physiological criteria.
Table of contents (télécharger
ce résumé et le sommaire de la
thèse)
- I. Introduction
-
- Why Study Yawning? .1
- All People Yawn, but No One Knows Why
.1
- Yawning is Not What It Seems .3
- Yawning as a Social Signal .4
-
- How to Study Yawning .6
- Using Multi-disciplinary Ethology and the
Evolutionary Paradigm .6
- Searching for a Homologue of the Human
Yawn .8
- Analysis of Yawn ëDesigní in
Humans and Between Species . 9
- The Evolutionary History of Yawning . 10
-
- II. Review of literature
-
- The Existence of Yawning Across the
Animal Kingdom . 13
- Yawning in Birds. 13
- Yawning in Fish. 16
- Yawning in Reptiles . 18
- Yawning in Non-primate Mammals . 19
- Yawning in Primates . 22
- Which Species of Primates Yawn?. 22
- What Types of Yawns Exists, and With What
Relative Frequencies Do They Occur?. 24
- Yawning Frequency Correlated With Age,
Hormones, and Drugs. 29
- Yawning Frequency Correlated With
Dominance. 31
- Yawning Frequency Correlated With Sex.
33
- Yawning Frequency Correlated With
Environment and Stress . 37
- The Relationship of Yawns to Canine
Displays and Threat Gestures. 42
- Yawning Contagion and the Communicative
Value of a Yawn. 45
- Discussion of Non-Human Literature on
Yawning. 46
- Observations and Studies of Human
Yawning. 48
- Physiological Studies. 48
- Behavioral Studies. 54
- Discussion of Human Literature. 57
-
- III. Predictions
-
- Pharmacological and Physiological
Influence. 61
- Psychological and Social Influence.
64
-
- IV. Why is yawning contagious
?
-
- Study Description. 73
- Introduction. 73
- Stimulus Development. 74
- Dominant Yawn Stimulus. 75
- Submissive Yawn Stimulus. 76
- Null Yawn Stimulus. 77
- Description of Subject Population .
77
- Methodology . 78
- Activities Involving Subjects. 78
- Method of Data Collection. 79
- Saliva Sample. 79
- Video Taping and Observation . 80
- Questionnaire . 81
- Data Disposition. 81
-
- V. Results
-
- Introduction. 83
- Study Effects. 84
- Effects of Stimulus vs. Control
Condition. 84
- Differences in Yawns Elicited Across
Experimental Conditions. 85
- Verification of Video Dominance
Manipulation. 86
- Effects of Dominance Perceptions. 91
- Subject Self-Reports of Dominance.
91
- Reports of Self-Dominance and
Actor-Dominance. 91
- Female vs. Male rating of Dominance.
97
- Effects of Relative Dominance on
Contagious Yawning. 99
- Effects of Sex Differences. 103
- Sex Differences in Yawning. 103
- Differences by Video and Sex in Yawning.
105
- Sex Differences by Target Differences in
Yawning. 107
- Self Reported Statistics of Yawning.
110
- Self Reports of Yawns. 110
- Differences by Video and Sex for Feels
Like Yawning. 111
- Control vs. Yawn Condition for Feels Like
Yawning. 111
- Female vs. Male for Feels Like Yawning.
111
- Sex Differences by Target Differences for
Feels Like Yawning. 112
- Latency and Yawn Contagion. 113
- Yawn Related Activities. 114
- Confounding Factors. 116
-
- VI. Summary of findings and
conclusions
-
- Findings and Conclusions. 119
- Discussion. 122
- Considerations for Future Studies.
122
- Final Discussion. 123
-
- Appendix
- a. questionnaire #1: for subjects who
watched a video with an actor in it
- b. questionnaire #2: for subjects who
watched a video with no actor in it
- c. recruitment flyer. 126
- d. consent forms. 128
- e. consent forms. 131
-
- Bibliography. 142
-
- -Legendre
R, Piéron H.
De la propriété
hypnotoxique des humeurs
développée au cours d'une veille
prolongée C.R. Société de
Biologie de Paris 1912; 70; 210-212
- -Bouyssou M,
Tricoire J Experimental detection of a
cervical arousal mechanism of yawning, enhancing
intracerebral (CSF) fluid pressure J Dental Res
1985; 64; 721
- -Lepp
FH Remarques sur la signification
physiologique du bâillement Bull Group Int
Rech Sci Stomtol Odontol 1982; 25; 251-290
- -Nolman
B Yawning, cerebral fluid and the lymphatic
pump 2006
- -Oreskovic D;
Klarica M; Vukic M The formation and
circulation of cerebrospinal fluid inside the
cat brain ventricles : a fact or an illusion ?
Neuroscience letters 2002; 327; 103-106
- -Patra P, Gunness
TK, Robert R Physiologic variations of the
internal jugular vein surface, role of the
omohyoid muscle, a preliminary echographic study
Surg Radiol Anat 1988; 10; 2; 107-12
- -Schniter E The
evolution of yawning : why do we yawn and why is
it contagious ? thèse 2001
- -Schroth G, Klose U
Cerebrospinal fluid flow; Physiology of
respiration-related pulsations. Neuroradiology
1992; 35; 1; 10-15
- -Walusinski
O Prostaglandines, adénosine, sommeil
& bâillements 2004
- -Woodbury R, B
Abretj Influence of dying gasps, yawns and
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