Intelligence is the one human trait that many continue to believe is genetically determined. The big question is whether or not intelligence is hereditary and therefore fixed, or due to the environment and changeable. In 1994, the controversy over this issue came up again with the publication of â€œThe Bell Curve: Intelligence and Class Structure in American Lifeâ€ written by Richard Herrnstein and Charles Murray. The authors argue that cognitive ability is substantially inherited, and therefore, it is virtually impossible to raise an individualâ€™s Intelligence Quotient, or IQ. Critics over this issue, however, state that the environment has an important role in determining intelligence and that if a childâ€™s environment is changed, their IQ can be changed as well.
Herrnstein and Murray also state that there is a correlation between IQ and behavior, and that because of this, the national IQ average is declining. They say the performance of a group can be predicted based on the groupâ€™s IQ average. Groups with low IQ tend to be poor, unemployed, on welfare, involved in criminal activities, and have more illegitimate children. Groups with a high