I'm going to post the abstract and "highlights" from this paper, purely because they are a seriously excellent summary of the paper:
Abstract: "Two dysgenic models of declining general intelligence have been proposed. The first posits that since the Industrial Revolution those with low g have had a reproductive advantage over those with high g. The second posits that relaxed purifying selection against deleterious mutations in modern populations has led to g declining due to mutation accumulation. Here, a meta-analytic estimate of the decline due to selection is computed across nine US and UK studies, revealing a loss of .39 points per decade (combined N = 202,924). By combining findings from a high-precision study of the effects of paternal age on offspring g with a study of paternal age and offspring de novo mutation numbers, it is proposed that, 70 de novo mutations per familial generation should reduce offspring g by 2.94 points, or .84 points per decade. Combining the selection and mutation accumulation losses yields a potential overall dysgenic loss of 1.23 points per decade, with upper and lower bound values ranging from 1.92 to .53 points per decade. This estimate is close to those from studies employing the secular slowing of simple reaction time as a potential indicator of declining g, consistent with predictions that mutation accumulation may play a role in these findings."
Highlights:
• g Losses due to dysgenic selection in nine US and UK studies are meta-analyzed.
• A decline of .39 points per decade is found.
• Mutation load should enhance losses due to selection
.
• Each year of paternal age adds 2 new mutations and reduces offspring g by .084 points.
• Combining selection and mutation losses reveals decadal g decline of 1.23 points.
• A decline of .39 points per decade is found.
• Mutation load should enhance losses due to selection
.
• Each year of paternal age adds 2 new mutations and reduces offspring g by .084 points.
• Combining selection and mutation losses reveals decadal g decline of 1.23 points.
I'd like to elaborate on the first dysgenic model, because I think I can add something worthwhile. Since the Industrial revolution, comfort has become more commonplace in countries, because production is more efficient. No longer does a person have to be self-sustaining, but rather needs only to specialise in an area of labour, in order to generate personal income. I think this is sufficiently self-evident to be assumed axiomatic.
Thus, as 3rd World immigrants, from areas such as Africa and the Middle East, are given access to these Western countries (U.S and U.K), we see their 3rd World breeding rates (addressed here: https://www.debateart.com/forum/topics/1065) lessened, but remain higher than that of native populations (http://www.pewforum.org/2015/04/02/muslims/pf_15-04-02_projectionstables75/). Considering the lower average I.Qs of African and Middle Eastern countries, when compared to Western White countries (https://www.worlddata.info/iq-by-country.php), we now have an elaboration on why the Industrial revolution could cause an I.Q. drop, therefore adding to the credibility of the paper.
