Analysis of information sources in references of the Wikipedia article "الخصوبة والذكاء" in Arabic language version.
There is no convincing evidence that any dysgenic trend exists. . . . It turns out, counterintuitively, that differential birth rates (for groups scoring high and low on a trait) do not necessarily produces changes in the population mean.
{{استشهاد بدورية محكمة}}: الوسيط |إظهار المؤلفين=6 غير صالح (مساعدة)Since the nineteenth century, a 'race deterioration' has been repeatedly predicted as a result of the excessive multiplication of less gifted people (Galton 1869; see also Fig. 9.1). Nevertheless, the educational and qualification level of people in the industrialized countries has risen strongly. The fact that the 'test intelligence' has also significantly increased (Flynn 2013), is difficult to explain for supporters of the dysgenic thesis: they suspect that the 'phenotypic intelligence' has increased for environmental reasons, while the 'genotypic quality' secretly decreases (Lynn 1996, p. 111). There is neither evidence nor proof for this theory.
{{استشهاد بدورية محكمة}}: الوسيط |إظهار المؤلفين=6 غير صالح (مساعدة)Since the nineteenth century, a 'race deterioration' has been repeatedly predicted as a result of the excessive multiplication of less gifted people (Galton 1869; see also Fig. 9.1). Nevertheless, the educational and qualification level of people in the industrialized countries has risen strongly. The fact that the 'test intelligence' has also significantly increased (Flynn 2013), is difficult to explain for supporters of the dysgenic thesis: they suspect that the 'phenotypic intelligence' has increased for environmental reasons, while the 'genotypic quality' secretly decreases (Lynn 1996, p. 111). There is neither evidence nor proof for this theory.
Since the nineteenth century, a 'race deterioration' has been repeatedly predicted as a result of the excessive multiplication of less gifted people (Galton 1869; see also Fig. 9.1). Nevertheless, the educational and qualification level of people in the industrialized countries has risen strongly. The fact that the 'test intelligence' has also significantly increased (Flynn 2013), is difficult to explain for supporters of the dysgenic thesis: they suspect that the 'phenotypic intelligence' has increased for environmental reasons, while the 'genotypic quality' secretly decreases (Lynn 1996, p. 111). There is neither evidence nor proof for this theory.
{{استشهاد بكتاب}}: صيانة الاستشهاد: علامات ترقيم زائدة (link)