Department of Basic Psychological Research, School of Psychology, University of Vienna, Vienna, Austria.
PLoS One. 2010 Dec 22;5(12):e14406. doi: 10.1371/journal.pone.0014406.
Generational IQ gains in the general population (termed the Flynn effect) show an erratic pattern across different nations as well as across different domains of intelligence (fluid vs crystallized). Gains of fluid intelligence in different countries have been subject to extensive research, but less attention was directed towards gains of crystallized intelligence, probably due to evidence from the Anglo-American sphere suggesting only slight gains on this measure. In the present study, development of crystallized intelligence in the German speaking general population is assessed.
METHODOLOGY/PRINCIPAL FINDINGS: To investigate whether IQ gains for crystallized intelligence are in progress in German-speaking countries, two independent meta-analyses were performed. By means of a cited reference search in ISI Web of Science, all studies citing test manuals and review articles of two widely-used salient measures of crystallized intelligence were obtained. Additionally, the electronic database for German academic theses was searched to identify unpublished studies employing these tests. All studies reporting participants mean IQ or raw scores of at least one of the two measures were included in the present analyses, yielding over 500 studies (>1,000 samples; >45,000 individuals). We found a significant positive association between years of test performance and intelligence (1971-2007) amounting to about 3.5 IQ points per decade.
CONCLUSIONS/SIGNIFICANCE: This study clearly demonstrates that crystallized IQ gains are substantial and of comparable strength as Flynn effects typically observed for measures of fluid intelligence in Central Europe. Since mean IQ was assessed in a large number of small, non-representative samples, our evidence suggests a remarkable robustness of these gains. Moreover, in both meta-analyses strength of gains was virtually identical. On the whole, results of the present study demonstrate a pervasive and generalizing Flynn effect in German-speaking countries.
一般人群中的代际智商增长（称为弗林效应）在不同国家以及不同的智力领域（流体智力与晶体智力）表现出不稳定的模式。不同国家的流体智力增长已经受到广泛研究，但晶体智力增长的关注较少，这可能是由于来自英美地区的证据表明在这一指标上只有轻微的增长。在本研究中，评估了德语人群中晶体智力的发展。
方法/主要发现：为了研究德语国家的晶体智力智商增益是否在进行中，进行了两项独立的荟萃分析。通过在 ISI Web of Science 中进行引用参考文献搜索，获得了引用两个广泛使用的晶体智力显著测量工具的测试手册和评论文章的所有研究。此外，还搜索了德国学术论文的电子数据库，以确定使用这些测试的未发表研究。所有报告参与者至少一项这两种测量工具的平均智商或原始分数的研究都包括在本分析中，产生了 500 多项研究（>1000 个样本；>45000 人）。我们发现，测试表现的年份与智力之间存在显著的正相关关系（1971-2007 年），相当于每十年增加约 3.5 个智商点。
结论/意义：本研究清楚地表明，晶体智力智商增益是实质性的，与中欧通常观察到的流体智力测量的弗林效应强度相当。由于大量小的、非代表性样本评估了平均智商，我们的证据表明这些增益具有显著的稳健性。此外，在两项荟萃分析中，增益的强度几乎相同。总的来说，本研究的结果表明德语国家存在普遍而普遍的弗林效应。
