| Some individuals show retardation even though no | | | | social learning are seen to be slow and below that |
| known genetic, hereditary, or physical cause can | | | | of the other children. |
| be found to account for it. Two clusters of | | | | Numerous studies have tried to show the |
| characteristics that have proven to be convenient | | | | relationship of low socioeconomic status to poor |
| descriptive categories, and which are related to | | | | learning abilities. In a home environment lacking |
| the underlying cause of retardation, are | | | | adequate heating, water, or safety precautions, |
| psychosocial disadvantage and emotional | | | | physical health care may be minimal. Lack of |
| disturbance. Some children obviously fit one | | | | exposure to intellectually stimulating opportunities |
| category, while others have characteristics of | | | | and poor child-rearing practices may reduce the |
| both. In all cases the children evidence signs of | | | | child's ability to respond to learning experiences. |
| retardation, slow learning, and poor academic | | | | Family tensions and pressures may create |
| performance. | | | | numerous obstacles to adequate interpersonal |
| Psychosocial disadvantage is diagnosed when four | | | | relationships. |
| criteria are present. First, the person must | | | | Emotional disturbance can interfere with |
| function at a retarded level. Second, there must | | | | educational performance. The child may be |
| be retardation within the immediate family. Third, | | | | withdrawn or excessively active. The more |
| no clear evidence of brain damage is present. | | | | severe the problem, the more likely that the |
| Fourth, the family background must include | | | | normal processes of school attendance, |
| impoverished living, care, and nutrition. This kind of | | | | homework, and socialization will be disrupted. |
| retardation will probably not show up until the child | | | | Retardation in this case may be clearly due to |
| enters school, at which time the academic and | | | | emotional factors but is often difficult to assess. |