From Scientific American:
Looks like Tiger Mom had it half-right: Motivation to work hard and good study techniques, not IQ, lead to better math skills, a new study shows. But there's a catch: The findings, published this month in the journal Child Development, show that keeping children's heads in the math books by force probably won't help. The analysis of more than 3,500 German children found those who started out solidly in the middle of the pack in 5th grade could jump to the 63rd percentile by 8th grade if they were very motivated and used effective learning strategies, said lead author Kou Murayama, a psychology researcher at the University of California Los Angeles. “The growth in math achievement was predicted by motivation and learning strategies,” Murayama told LiveScience. “Given that IQ did not show this kind of effect, we think this is impressive.”
More here.