creators_name: Bracha, Stefan
creators_name: Bracha, Adam S.
creators_name: Williams, Andrew E.
creators_name: Ralston, Tyler C.
creators_name: Matsukawa, Jennifer M.
type: journalp
datestamp: 2006-08-01
lastmod: 2011-03-11 08:56:33
metadata_visibility: show
title: The human fear-circuitry and fear-induced 
fainting in healthy individuals 
The paleolithic-threat hypothesis 
ispublished: pub
subjects: bio-evo
subjects: psycphs
full_text_status: public
keywords: fainting, human evolution, war, combat, fear-circuitry, androgens, stress-induced disorders 
abstract: The Paleolithic-Threat 
hypothesis reviewed here posits 
that habitual efferent fainting can 
be traced back to fear-induced 
allelic polymorphisms that were 
selected into some genomes of 
anatomically, mitochondrially, and 
neurally modern humans (Homo 
sapiens sapiens) in the Mid-Paleolithic because of the survival 
advantage they conferred during 
periods of inescapable threat. We 
posit that during Mid-Paleolithic 
warfare an encounter with “a 
stranger holding a sharp object” 
was consistently associated with 
threat to life. A heritable hard-
wired or firm-wired (prepotentiated) predisposition to abruptly 
increase vagal tone and collapse 
flaccidly rather than freeze or 
attempt to flee or fight in response 
to an approaching sharp object, a 
minor injury, or the sight of blood, 
polymorphism for the hemodynamically “paradoxical” flaccid-
immobility in response to these 
stimuli may have increased some 
non-combatants’ chances of survival. This is consistent with the 
unusual age and sex pattern of 
fear-induced fainting. The Paleolithic-Threat hypothesis also predicts a link to various hypo-androgenic states (e.g. low dehydroxyepiandrosterone-sulfate. We offer 
five predictions testable via epidemiological, clinical, and ethological/primatological methods. The 
Paleolithic-Threat hypothesis has 
implications for research in the 
aftermath of man-made disasters, 
such as terrorism against civilians, 
a traumatic event in which this 
hypothesis predicts epidemics of 
fear-induced fainting
date: 2005
date_type: published
publication: Clinical Autonomic Research
volume: 15
pagerange: 238-241
refereed: TRUE
citation:   Bracha, Dr. Stefan and Bracha, Adam S. and Williams, Dr. Andrew E. and Ralston, Tyler C. and Matsukawa, Jennifer M.  (2005) The human fear-circuitry and fear-induced fainting in healthy individuals The paleolithic-threat hypothesis.  [Journal (Paginated)]     
document_url: http://cogprints.org/5035/1/2005_C.A.R_review_FEAR-CIRCUITRY-DRIVEN_FAINTS.pdf