Table 7.

Rank ordered fold difference between brain structure volumes in humans and chimpanzees

Structure	Human versus chimpanzee fold difference	Data source
Brain	3.6	Chimpanzee (n = 12)—the present study; human (n = 10)—Uylings et al. (2006)
Neocortical gray	4.0	Chimpanzee (n = 6) and human (n = 6)—Rilling and Insel (1999)
Frontal cortex	4.6	Chimpanzee (n = 6) and human (n = 10)—Semendeferi et al. (2002)
Area 44 left	6.6	Chimpanzee (n = 12)—the present study; human (n = 10)—Uylings et al. (2006)
Area 10 right	6.3	Chimpanzee (n = 1) and human (n = 1)—Semendeferi et al. (2001)
Area 45 left	6.0	Chimpanzee (n = 12)—the present study; human (n = 10)—Uylings et al. (2006)
Area 45 right	5.0	Chimpanzee (n = 12)—the present study; human (n = 10)—Uylings et al. (2006)
Area 44 right	4.1	Chimpanzee (n = 12)—the present study; human (n = 10)—Uylings et al. (2006)
Area V1 left	1.8	Chimpanzee (n = 7) and human (n = 10)—de Sousa (2008)
Area 13 right	1.4	Chimpanzee (n = 1) and human (n = 1)—Semendeferi et al. (1998)

Note: All data are from either in vivo MRI or shrinkage-corrected measurements of histological sections.