What does the bell curve tell us about intelligence?

The bell curve uses the standard deviation to show how all scores are dispersed from the average score. Any IQ score that falls within one standard deviation above and below the mean (between 85 and 115) is considered average, and 68\% of the population has IQ scores in this range.

Does birth order affect intelligence?

Using this more accurate method, researchers have found that birth order does not affect intelligence, and that differences in intelligence observed in previous trials are most likely due to external factors such as parents’ intelligence or economic disadvantages more often faced by larger families.

What assumption do the authors of The Bell Curve make regarding intelligence?

Stephen Jay Gould wrote that the “entire argument” of the authors of The Bell Curve rests on four unsupported, and mostly false, assumptions about intelligence: Intelligence must be reducible to a single number. Intelligence must be capable of rank ordering people in a linear order.

How does IQ follow a normal distribution?

One example of a variable that has a Normal distribution is IQ. In the population, the mean IQ is 100 and it standard deviation, depending on the test, is 15 or 16. If a large enough random sample is selected, the IQ distribution of the sample will resemble the Normal curve.

Does the first-born have a higher IQ?

First-born children’s thinking skills outperform their siblings because they receive more mental stimulation from their parents in their early years, research suggests. First borns score higher than their siblings in IQ tests as early as age one, the study has found.

Why are first-born smarter?

“The first-borns scored higher on tests including reading and picture vocabulary, which according to the researchers, could reflect the ‘birth order effect’. This means children born earlier in a family go on to have a better level of education and earn higher wages further down the line.”

What does a bell curve indicate?

Key Takeaways. A bell curve is a graph depicting the normal distribution, which has a shape reminiscent of a bell. The top of the curve shows the mean, mode, and median of the data collected. Its standard deviation depicts the bell curve’s relative width around the mean.