It is a generally accepted fact that human beings are a product of heredity and environment. Out of the product come both our individuality and our individual differences. If a person with high hereditary potential is placed in a poor environment, his measured ability will probably be low. If hereditary potential is low, even the best environment will be able to take the person ahead only so far.
One may conclude that heredity provides a potential, which may or may not be developed by environment. Let us look at some animal studies on heredity and environmental stimulation since good control studies are so difficult using human subjects.
It has been found possible to breed rat strains with different amounts of inherited learning ability. In one laboratory situation, the learning ability of a large number of rats was studied by compelling them to run mazes. The animals were divided into two groups. Group 1 was composed of animals that made few errors and were .mated together. Group 2, composed of those that made many errors, were likewise bred together. Succeeding generations in each group were tested for learning ability and selectively bred for intelligence. By the seventh generation, there was little or no overlap in the scores of the bright and dull groups.
In other studies rats equal in heredity were placed in twa groups by using the split-litter method. One group was reared in a very restricted environment. Each animal was isolated in its own cage with no opportunity to socialize with other rats. The cage was bare, and there was no opportunity either to seek out or to solve problems. The animals in the other groups were raised in a stimulating environment, called by ooe psychologist an "amusement park for rats." Here the subjects were given objects to play with; barriers and pathways provided opportunities for exploration.
When the animals grew up, they were tested for their problemsolving ability. The group that had grown up in isolation was found to be inferior to those raised in the richer environment. Furthermore, the superiority of the second group was found to be lasting. Similar studies with other animals has shown the same sort of results. However, this superiority in performance did not carry over into the heredity strain for succeeding generatio:ls.
To conclude, nature and nurture work together, but one of them may play a larger role than the other in producing some given behavior.
One may conclude that heredity provides a potential, which may or may not be developed by environment. Let us look at some animal studies on heredity and environmental stimulation since good control studies are so difficult using human subjects.
It has been found possible to breed rat strains with different amounts of inherited learning ability. In one laboratory situation, the learning ability of a large number of rats was studied by compelling them to run mazes. The animals were divided into two groups. Group 1 was composed of animals that made few errors and were .mated together. Group 2, composed of those that made many errors, were likewise bred together. Succeeding generations in each group were tested for learning ability and selectively bred for intelligence. By the seventh generation, there was little or no overlap in the scores of the bright and dull groups.
In other studies rats equal in heredity were placed in twa groups by using the split-litter method. One group was reared in a very restricted environment. Each animal was isolated in its own cage with no opportunity to socialize with other rats. The cage was bare, and there was no opportunity either to seek out or to solve problems. The animals in the other groups were raised in a stimulating environment, called by ooe psychologist an "amusement park for rats." Here the subjects were given objects to play with; barriers and pathways provided opportunities for exploration.
When the animals grew up, they were tested for their problemsolving ability. The group that had grown up in isolation was found to be inferior to those raised in the richer environment. Furthermore, the superiority of the second group was found to be lasting. Similar studies with other animals has shown the same sort of results. However, this superiority in performance did not carry over into the heredity strain for succeeding generatio:ls.
To conclude, nature and nurture work together, but one of them may play a larger role than the other in producing some given behavior.
