Bell Curve and Correlational Research
Richard J. Herrnstein and Charles Murray, authors of The Bell Curve, have received criticism for their inability to establish the "truth" in their research of intelligence. Rather than using objective tests to determine if their findings were valid (e.g., control groups and follow-up studies; varying conditions; factoring in margin for error), they assumed that their research findings were accurate based on one premise - the IQ scores of students after 1950 as opposed to the scores of those in earlier years. They offer graphs and tables to "prove" that intelligence determines social status more than inherited status (i.e., one's parents being of high social standing). But although they seem to have definitive evidence, their method was flawed because they failed to take into account that research methods are not the same in this present day as they were 20 or 30 years ago. Additionally, although they insist that one's social standing does not predict eventual intelligence - for example, there are more people with higher IQs now than prior to 1950 - it does not address the fact that the poverty level is at a lower percentage than it was in 1950, which means that not as many people would, by their determinations, have lower IQs because not as many are living at poverty level. The authors did not consider all the alternative when they put together their research findings. They did not, for example, allow for a variable such as a non-related family member being brought up in a particular household (such as adopted children), and how that social standing remained the same, even though the child had a different genetic make-up. Such children may differ in innate intelligence from biological children rise but often remain in the same social class because they are raised in the same way as parents would raise a biological child, and that has a lot to do with the child's cognitive ability. Herrnstein and Murray would have been better advised to do a broader study that allowed for variables in economic background and the changes in economic climate in the years they insist the curve went up due to educational opportunities.