This is not true at all. I wrote a summary of a summary of some of the findings on IQ here: Intelligence: A Very Short Introduction Review The vast majority of research suggests that 1. read more
In that all IQ really indicates is one's ability to do IQ tests, you can clearly improve your IQ score with practice. Also increasing physical infirmity will have a bad effect when the health of the brain is affected. read more
IQ is a mathematical ratio. Myth: IQ is fixed; it doesn't change. The second most common IQ myth is that a person's IQ never changes. People who are found to be academically poor in their childhood are tagged as one with low IQ for the rest of their lives. Reality. Since IQ is a ratio, the number changes depending on what a person learns. read more