Heredity and Environment:
Heredity provided the physical body to be developed with certain inherent capabilities while environment provides for the maturation and training of the organism. In 1940 Newman concluded that variations in I.Q. were determined about 68% by heredity and 32% by environment.
During an individual’s life time variation in I.Q. is due to environment, since the heredity cannot change. Improved nutrition health, an stimulus situations would account for this change. Environment of children ages 2 to 4 years appears to be critical since the child normally learns language at this time. Better homes, school, medical facilities, less economic discrimination. Provides a mean for achieving a mentally able population.
- Age:
A person who bright or dull in childhood tends to remain bright or dull throughout his life. Growth I intelligence can continue through the early twenties, person achieves his maximum 10 at about 20 years are and remain stable till 10 years and decreases after that. Some abilities remain constant while others decline rapidly due to decline in physical efficiency. It is observed that the more intelligent person has more rapid of mental growth and continues to develop longer than does the mentally less able.
Race and Nationality:
There is no prominent evidence to show that race in a factor for determining intellectual level. Difference exist between families are due to environment. The differences in races are also due to opportunity for training in early years.
All evidence indicates that there is little or no difference in inherited intellectual capacity due to race. There are differences, mostly due to opportunities for training and learning. The idea of inferior races due to heredity is not true.
- Culture:
Answer in intelligent test question are highly cultural. Cultural will determine the degree of a person’s attitude and abilities.
- Health and Physical Development:
Physical and mental health is related to one’s ability to gain desired achievement. A mental activity with delicate health, one may not possess enough energy to engage in mental activity to the extent that he achieves success. Physical defects such as in complete maturation of brain cells sensory and physical handicaps many interfere with observable intelligent behavior. Diseases also affect intelligence. Emotional bodies may interferes one’s ability. Unfavorable health affects mental status of the individual.
- Sex:
It is a popular belief that boys are suppose to be more intelligent than girls. The research studies have shown that there is no significant differences between the sexes, on the average, girls seems to show slight superiority in language, memory and appreciation. Differences in intelligence are caused partly by environmental conditions
- Social and Economic Conditions:
Home plays a significance role in the early developmental years. Home conditions influence on behaviours attitude. The financial status or the parents, neighborhood and environmental conditions also affect on the intelligence but due to their soci-economic status.