The Male Warrior Hypothesis: Testosterone-related Cooperation and Aggression in the Context of Intergroup Conflict
Journal
Scientific Reports
ISSN
2045-2322
Date Issued
2020
Author(s)
José Antonio Muñoz Reyes
Universidad de Playa Ancha de Ciencias de la Educación
N. Valenzuela
Pablo Polo Rodrigo
Universidad de Playa Ancha de Ciencias de la Educación
P. Pavez
O. Ramírez-Herrera
D. Díaz
M. Pita
Type
Resource Types::text::journal::journal article
Abstract
<jats:title>Abstract</jats:title><jats:p>The Male Warrior Hypothesis (MWH) establishes that men’s psychology has been shaped by inter-group competition to acquire and protect reproductive resources. In this context, sex-specific selective pressures would have favored cooperation with the members of one’s group in combination with hostility towards outsiders. We investigate the role of developmental testosterone, as measured indirectly through static markers of prenatal testosterone (2D:4D digit ratio) and pubertal testosterone (body musculature and facial masculinity), on both cooperation and aggressive behavior in the context of intergroup conflict among men. Supporting the MWH, our results show that the intergroup conflict scenario promotes cooperation within group members and aggression toward outgroup members. Regarding the hormonal underpinnings of this phenomenon, we find that body musculature is positively associated with aggression and cooperation, but only for cooperation when context (inter-group competition) is taken into account. Finally, we did not find evidence that the formidability of the group affected individual rates of aggression or cooperation, controlling for individual characteristics.</jats:p>
Subjects
adult
;
aggression
;
competitive behavior
;
conflict, psychological
;
group processes
;
hostility
;
humans
;
male
;
psychology, social
;
testosterone
;
warfare
;
young adult
;
testosterone
;
adult
;
aggression
;
competitive behavior
;
group process
;
hostility
;
human
;
male
;
metabolism
;
psychology
;
social psychology
;
warfare
;
young adult