Hi Lex, great interview. I would love to hear a counter perspective to Haier. There seems to be a compelling body of research to suggest that IQ can change through repeated IQ testing, and that IQ scores are not immutable. The teen brain for example has a particularly high plasticity with MRI brain scans revealling that drifts in IQ occured coincident with structural changes in cerebral grey matter.  <br>Thank you for the excellent podcast.,(reply>), My understanding is that most of the improvements in adult IQ tend not to be g-loaded. While e.g., repeatedly taking an IQ test can improve your score, the impact of these sorts of interventions tends to decrease the more a test reflects the g factor.,(reply>), No. You should probably reread the literature on the subject… the actual research literature and not what the popular press writes!,(reply>), IQs never change once brain developement ends by your mid 20s