3304 Children, 10-14 years, grades 1-8
| Average grades completed | % lost | |
| Children having no physical defects | 4·94 | |
| Children having enlarged glands | 4·20 | 14·9 |
| Children having defective vision | 4·94 | 0 |
| Children having defective breathing | 4·58 | 7·2 |
| Children having defective teeth | 4·65 | 5·9 |
| Children having hypertrophied tonsils | 4·50 | 8·9 |
| Children having adenoids | 4·24 | 14·1 |
| Children having other defects | 4·52 | 8·5 |
Cornell reports several investigations in the Psychological Clinic, January and May, 1908. Three of these, in which children were rated on the basis of grades received in school work, are here combined to show the grades of normal children, "average" children, generally defective children, those possessing adenoids and tonsils, and the deaf.
| No. of cases | Normal | Average | General Defective | Adenoids & Tonsils | Adenoids | Deaf |
| Allison | 219 | |||||
| 9th St. | 64 | 84 | 21 | 8 | ||
| Claghorn | 179 | 252 | 13 | |||
| Grade in language | ||||||
| 9th St. | 72·9 | 70·5 | 63·3 | 60 | ||
| Claghorn | 74·4 | 72·7 | 71·4 | |||
| Grade in Arith. | ||||||
| 9th St. | 75·5 | 74 | 70 | 66·7 | ||
| Claghorn | 72 | 70 | 65·1 | |||
| Grade in spelling | ||||||
| 9th St. | 75·4 | 72·8 | 64·8 | 65 | ||
| Grade in geography | ||||||
| Claghorn | 76·6 | 76·5 | 76·2 | |||
| Average of grades | ||||||
| Allison | 75 | 74 | 72·6 | 72 | 67 | |
| 9th St. | 74·6 | 72·4 | 66 | 63·9 | ||
| Claghorn | 74·3 | 73·1 | 70·8 | |||
An additional investigation of four classes in the same grammar grade of the Claghorn School gives the following results:
| Class 1 Bright | Class 15 Children | Class 9 Dull | Class 11 Dullest | |
| Number of children | 50 | 39 | 32 | 29 |
| Normal | 36 | 32 | 20 | 13 |
| Defective | 14 | 7 | 12 | 16 |
| Percentage of normal | 72 | 82 | 62·5 | 44·8 |
In the same article, Dr. Cornell gives the results of another study of Philadelphia schools, made in 1906. The study comprised a comparison of children exempt from examinations on account of high standing, with those not exempt. The results follow:
| Exempt Normal | Children Defective | Non-exempt Normal | Children Defective | |||
| 9th St. Primary | 56 | 28 | 39 | 38 | ||
| Rutledge School | 87 | 35 | 75 | 34 | ||
| Allison School | 128 | 65 | 81 | 49 | ||
| Camac School | 183 | 71 | 103 | 75 | ||
| Claghorn School | 193 | 61 | 127 | 66 | ||
| 647 | 260 | 425 | 262 | |||
| Percentage Defective | 28·8 | 38·1 |
When the four classes of bright and dull children were examined again, and the different sorts of defects compared for the groups, enlarged tonsils, adenoids, deafness, and nasal catarrh, were found to occur much more frequently among the two classes of duller children.
| Class 1 Bright | Class 15 Children | Class 9 Dull | Class 11 Dullest | |
| Number of children | 50 | 39 | 32 | 29 |
| Nose and throat conditions, number defective | 6 | 4 | 9 | 9 |
| Tonsils | 3 | 4 | 3 | 3 |
| Adenoids | 2 | 1 | 5 | 6 |
| Deaf | 2 | 5 | 1 | |
| Catarrh | 2 | 3 | ||
| Percentage of children, nose and throat defects | 12 | 10·2 | 28·1 | 31 |