Table 5.

Groups of significantly different linear distances in humans.

Brain region	Linear distance	Apes/Great apes	Bonobos	Chimpanzees	Gorillas	Orangutans	Gibbons
Significantly smaller in humans
Amygdalae	26–27	0.79	0.78	0.89	• 0.91	0.74	0.70
	14–26	0.83	0.82	0.86	• 0.94	0.80	0.77
	14–27	0.83	0.84	0.87	• 0.93	0.80	0.74
	15–26	0.80	0.82	0.81	0.83	0.75	0.78
	15–27	0.81	0.85	0.80	0.81	0.77	0.78
	22–26	0.83	0.83	0.81	0.82	• 0.91	0.77
	23–27	0.80	0.79	0.79	0.85	0.83	0.76
	24–26	0.84	• 0.92	0.82	0.89	0.79	0.79
	25–27	0.82	0.88	0.81	0.87	0.74	0.81
Fronto- parietal region	3–7	• 0.94	0.90	• 0.94	• 0.92	• 0.97	• 1.02
	4–8	0.80	0.78	0.80	0.76	0.81	0.83
	5–9	• 0.90	0.80	• 0.89	• 1.00	0.78	• 1.15
	6–10	• 0.87	0.74	0.82	⋆ 1.27	• 0.98	1.16
	3–9	0.81	0.72	0.85	0.82	• 0.84	0.83
	4–10	0.88	0.81	0.88	0.88	0.86	• 0.99
Occipital region	11–12	0.81	0.85	• 0.91	0.88	• 0.80	0.62
	28–29	0.80	0.70	0.82	0.87	0.88	0.82
	11–28	0.82	0.68	• 1.10	• 1.00	• 0.91	0.65
	12–29	• 0.93	0.78	• 1.05	⋆ 1.18	• 0.90	• 0.95
	11–29	0.87	0.77	• 0.96	• 1.09	0.86	0.84
	12–28	0.81	0.72	• 0.98	0.90	0.87	0.68
Significantly greater in humans
Frontal region	1–2	1.35	1.18	1.27	2.29	1.30	1.74
	1–3	1.14	1.15	1.15	1.12	1.24	• 1.05
	2–4	1.17	1.22	1.19	1.11	1.23	• 1.07
	1–4	1.19	1.21	1.19	1.23	1.21	1.14
	2–3	1.15	1.13	1.16	1.18	1.20	1.10
	1–13	1.11	1.16	• 1.06	1.15	1.12	• 1.07
	2–13	1.10	1.14	• 1.06	1.11	1.13	• 1.06
	1–22	1.13	1.12	1.12	1.15	1.21	• 1.08
	2–23	1.12	1.10	1.15	1.13	1.21	• 1.05
	1–5	1.17	1.23	1.21	• 1.04	1.21	• 1.04
	2–6	1.20	1.31	1.33	• 0.97	1.11	• 1.07
	1–6	1.21	1.33	1.29	• 1.03	1.13	1.11
	2–5	1.16	1.22	1.20	• 1.06	1.21	• 1.06
Intraparietal sulcus	9–10	1.14	1.23	1.11	• 1.09	• 0.97	1.25
	9–28	1.12	1.19	• 1.03	• 0.97	• 0.98	1.38
	10–29	• 1.05	1.12	• 1.02	• 0.92	• 1.07	• 1.06

The first column refers to the anatomical region spanned by the linear distances between landmarks listed in Column 2. Values within the remainder of the cells indicate the ratio with respect to that specific linear distance, with the human sample as the numerator. The column entitled, “Apes/Great apes” collapses the human vs. all other apes and human vs. other great apes comparisons into a single column, as the average ratios were the same in the two comparisons.

^•indicates ratios that are not significantly different.

^⋆indicates ratios that are significantly greater in humans for a particular comparison, when the remainder of the comparisons for that ratio are significantly smaller.