Intelligence may be changeable, but this is a truism: I can 'change' my intelligence by eating some paint chips or taking a baseball bat to my head.<p>What isn't suggested by 'many psychological studies' is that IQ can be reliably, long-term, and over general populations by any particular technique. And that's what everyone <i>wants</i> to exist and will read into a statement like that. So, based on the abstract, this study boils down to a good motivation technique.<p>(I say reliably because with 0.05 significance there will be many false results; long-term because short-term studies will show anything you want them to; and over general populations because there are small deprived groups in which one can easily boost IQ long-term - eg. children in the Balkans with iodine deficiencies.)<p>EDIT: Also note that the researchers point to increased grades - <i>not</i> increased IQ scores. If they have enough participation, time, and cooperation from these students to do all this teaching &#38; motivating, then it is inexplicable - if they think they're actually boosting IQ - to have not given the students a quick hour-long IQ test; but this omission is quite understandable if they don't think their intervention is actually increasing anyone's IQ but their motivation.