Editing The Bell Curve (section)

===Introduction===

The book starts with an introduction that appraises the history of the concept of intelligence from [[Francis Galton]] to modern times. Spearman's introduction of the [[g factor (psychometrics)|general factor of intelligence]] and other early advances in research on intelligence are discussed along with a consideration of links between intelligence testing and racial politics. The 1960s are identified as the period in American history when social problems were increasingly attributed to forces outside the individual. This egalitarian ethos, Herrnstein and Murray argue, cannot accommodate biologically based individual differences.<ref name="devlin">{{cite book |title=Intelligence, Genes, and Success: Scientists Respond to The Bell Curve |url=https://archive.org/details/intelligencegene00bern |url-access=registration |first1=Bernie |last1=Devlin |first2=Stephen E. |last2=Fienberg |first3=Daniel P. |last3=Resnick |first4=Kathryn |last4=Roeder |author4-link=Kathryn Roeder |publisher=Springer Science & Business Media |year=1997 |isbn=978-0-387-94986-4}}</ref>

The introduction states six of the authors' assumptions, which they claim to be "beyond significant technical dispute":<ref name="HerrnsteinMurray2010">{{cite book |first1=Richard J. |last1=Herrnstein |first2=Charles |last2=Murray |title=The Bell Curve: Intelligence and Class Structure in American Life |url=https://books.google.com/books?id=s4CKqxi6yWIC |date=11 May 2010 |publisher=Simon and Schuster |isbn=978-1-4391-3491-7 |pages=22–23}}</ref>
# There is such a difference as a general factor of cognitive ability on which human beings differ.
# All standardized tests of academic aptitude or achievement measure this general factor to some degree, but IQ tests expressly designed for that purpose measure it most accurately.
# IQ scores match, to a first degree, whatever it is that people mean when they use the word intelligent, or smart in ordinary language.
# IQ scores are stable, although not perfectly so, over much of a person's life.
# Properly administered IQ tests are not demonstrably biased against social, economic, ethnic, or racial groups.
# Cognitive ability is substantially [[Heritability|heritable]], apparently no less than 40 percent and no more than 80 percent.
At the close of the introduction, the authors warn the reader against committing the [[ecological fallacy]] of inferring things about individuals based on the aggregate data presented in the book. They also assert that intelligence is just one of many valuable human attributes and one whose importance among human virtues is overrated.<ref name="devlin"/>