TY  - JOUR
PY  - 2012//
TI  - Face to face with the social brain
JO  - Philosophical transactions of the Royal Society of London. Series B, Biological sciences
A1  - Dobson, Seth
SP  - 1901
EP  - 1908
VL  - 367
IS  - 1597
N2  - Recent comparative evidence suggests that anthropoid primates are the only vertebrates to exhibit a quantitative relationship between relative brain size and social group size. In this paper, I attempt to explain this pattern with regard to facial expressivity and social bonding. I hypothesize that facial motor control increases as a secondary consequence of neocortical expansion owing to cortical innervation of the facial motor nucleus. This is supported by new analyses demonstrating correlated evolution between relative neocortex size and relative facial nucleus size. I also hypothesize that increased facial motor control correlates with enhanced emotional expressivity, which provides the opportunity for individuals to better gauge the trustworthiness of group members. This is supported by previous evidence from human psychology, as well as new analyses demonstrating a positive relationship between allogrooming and facial nucleus volume. I suggest new approaches to the study of primate facial expressivity in light of these hypotheses.<p />  <p>Language: en</p>
LA  - en
SN  - 0962-8436
UR  - http://dx.doi.org/10.1098/rstb.2011.0224
ID  - ref1
ER  -