The notion that people who sleep late have higher IQ is not necessarily true. While it is true that there are some studies that have found correlations between late sleepers and higher IQ, there are a number of other factors that must be taken into account when considering this hypothesis.
First, it is important to note that the studies conducted so far have largely been correlational, meaning that they can only show that there is an association between late sleepers and higher IQ, but not that one causes the other. It is possible that the two are related, but it is also possible that they are unrelated and that the association is due to other factors such as lifestyle or genetics.
Second, it is important to consider the environment in which the individuals studied live. For instance, those who live in more affluent areas may have more access to educational resources and other opportunities that could lead to higher IQ scores. Therefore, it is possible that the association between late sleepers and higher IQ is due to factors other than sleep itself.
Finally, it is important to remember that IQ is not the only measure of intelligence. There are a number of other factors that can contribute to an individual's overall intelligence, such as creativity, problem solving, and emotional intelligence. Therefore, it is possible that individuals who sleep late may have higher scores on these other measures of intelligence, even if they do not necessarily have higher IQ scores.
In conclusion, the notion that people who sleep late have higher IQ is not necessarily true. While there is some evidence that suggests a correlation between the two, there are a number of other factors that must be taken into consideration when evaluating this hypothesis.