Table 1.

Mean organ weight in percent of body weight (+/− SEM) in the parental generation (P0) and the fifth generation (S5) selected for “High” or “Low” fear of humans, or unselected.

Ratio organ/body weight	P0			S5
				High			Unselected			Low
	Mean	SEM		Mean	SEM		Mean	SEM		Mean	SEM
Heart	0.398	±	0.010	0.483		0.019	0.395		0.018	0.379	±	0.022
Total testis	0.590	±	0.043	0.72±2	±	0.036	0.471	±	0.076	0.654	±	0.033
Proportion left/right testis	0.836	±	0.021	1.321	±	0.045	1.272	±	0.090	1.238	±	0.037
Liver	1.963	±	0.117	1.958	±	0.179	1.757	±	0.211	1.432	±	0.129
Spleen	0.085	±	0.003	0.115	±	0.006	0.085	±	0.005	0.076	±	0.007