Good comment! The paper you link also specifically mentions the results from Scandinavia: > Our study did not find evidence for the plateauing or decline of t

Good comment! The paper you link also specifically mentions the results from Scandinavia: > Our study did not find evidence for the plateauing or decline of the Flynn effect in the United States, as has been documented in Norway (Sundet et al., 2004) and Denmark (Teasdale & Owen, 2008; Teasdale & Owen, 2005), respectively. Table 5.6 in the WAIS-IV manual (Wechsler, 2008) summarizes an excellent planned comparison of the WAIS-III (standardized in 1995) and the WAIS-IV (standardized in 2005) scores administered in counterbalanced order to 240 examinees. This table shows results similar to our meta-analysis, with average WAIS-III scores about 3 points higher than WAIS-IV scores. In addition, the effect was similar across age and ability level cohorts. To the extent that the United States and Scandinavia differ on at least the variables proposed to be related to the plateauing of scores in Scandinavia (e.g., family life factors [Sundet et al., 2004] and educational priorities [Teasdale & Owen, 2008; Teasdale & Owen, 2005]), we might anticipate the difference in IQ score patterns noted. For example, Scandinavia’s parental leave and subsidized childcare might be indices of optimal socioenvironmental conditions and are generous relative to the United States.