Schuster's results for the inheritance of deaf-mutism; Mr. Heron's results for the inheritance of the insane diathesis, and my own work on pulmonary tuberculosis. It is worth noting that these results are all first-fruits of Mr. Galton's foundation of a eugenics laboratory.
| Table IV. | |||
| Pathological Inheritance | |||
| Condition | Investigator | Parental | Fraternal |
| Deaf-mutism | Schuster | .54 | .73 |
| Insanity | Heron | .58 | .48 |
| Pulmonary tuberculosis | Pearson | .50 | .48 |
| Mean value | —— | .54 | .56 |
Now it must be admitted at once that these diseased states are far harder to deal with than simple quantitative characters. Their treatment involves more assumptions, and the data are less trustworthy.
| Table V. | |||
| School Observations. Resemblance of Siblings | |||
| Physical Characters | |||
| Character | Boys | Girls | Boy and Girl |
| Health | .52 | .51 | .57 |
| Eye color | .54 | .52 | .53 |
| Hair color | .62 | .56 | .55 |
| Curliness | .52 | .52 | .52 |
| Cephalic index | .49 | .54 | .43 |
| Head length | .50 | .43 | .46 |
| Head breadth | .59 | .62 | .54 |
| Head height | .55 | .52 | .49 |
| Mean | .54 | .53 | .51 |
| Table VI. | |||
| School Observations. Resemblance of Siblings | |||
| Physical Characters | |||
| Character | Boys | Girls | Boy and Girl |
| Vivacity | .47 | .43 | .49 |
| Assertiveness | .53 | .44 | .52 |
| Introspection | .59 | .47 | .63 |
| Popularity | .50 | .57 | .49 |
| Conscientiousness | .59 | .64 | .63 |
| Temper | .51 | .49 | .51 |
| Ability | .46 | .47 | .44 |
| Handwriting | .53 | .56 | .48 |
| Mean | .52 | .51 | .52 |
But from what I show in this table I think we may safely draw two conclusions: (a) the tendency to diseases of mind and body is inherited; (b) this inheritance may be slightly greater, it is hardly likely to be less, than the inheritance of quantitatively measurable physical characters.
