Editing Flynn effect (section)

==IQ group differences==
[[File:Flynn-–-World-Regions.png|thumb|Gains in IQ that different world regions have made since the first year for which data is available for a particular region.]]
{{see also|Nations and intelligence|Race and intelligence|Sex differences in intelligence}}
If the Flynn effect has ended in developed nations but continues in less developed ones, this would tend to diminish [[Nations and intelligence|national differences in IQ scores]].<ref name = "reversal" />

Also, if the Flynn effect has ended for the majority in developed nations, it may still continue for minorities, especially for groups like immigrants where many may have received poor nutrition during early childhood or have had other disadvantages. A study in the [[Netherlands]] found that children of non-Western immigrants had improvements for [[g factor (psychometrics)|g]], educational achievements, and work proficiency compared to their parents, although there were still remaining differences compared to ethnic Dutch.<ref name=Nijenhuis04/>

In the United States, the IQ gap between black and white people was gradually closing over the last decades of the 20th century, as black test-takers increased their average scores relative to white test-takers. For instance, Vincent reported in 1991 that the black–white IQ gap was decreasing among children, but that it was remaining constant among adults.<ref>{{Cite journal |last=Vincent |first=Ken R. |date=March 1991 |title=Black/white IQ differences: Does age make the difference? |journal=Journal of Clinical Psychology |volume=47 |issue=2 |pages=266–270 |doi=10.1002/1097-4679(199103)47:2<266::aid-jclp2270470213>3.0.co;2-s |pmid=2030133 }}</ref> Similarly, a 2006 study by Dickens and Flynn estimated that the difference between mean scores of black people and white people closed by about 5 or 6 IQ points between 1972 and 2002,{{sfn|Dickens|Flynn|2006}} a reduction of about one-third. In the same period, the educational achievement disparity also diminished.<ref>Neisser, Ulric (Ed). 1998. The rising curve: Long-term gains in IQ and related measures. Washington, DC, US: American Psychological Association</ref> Reviews by Flynn and Dickens,<ref>{{Cite journal |last1=Dickens |first1=William T |last2=Flynn |first2=James R |year=2006 |title=Black Americans Reduce the Racial IQ Gap: Evidence from Standardization Samples |url=http://www.brookings.edu/views/papers/dickens/20060619_iq.pdf |url-status=dead |journal=Psychological Science |volume=17 |issue=10 |pages=913–20 |citeseerx=10.1.1.186.2540 |doi=10.1111/j.1467-9280.2006.01802.x |pmid=17100793 |s2cid=6593169 |archive-url=https://web.archive.org/web/20091009095003/http://www.brookings.edu/views/papers/dickens/20060619_IQ.pdf |archive-date=2009-10-09 }}</ref> [[Nicholas Mackintosh]],<ref>{{Cite book |last=Mackintosh |first=N. J. |author-link=Nicholas Mackintosh|title=IQ and Human Intelligence |publisher=Oxford University Press |year=2011 |isbn=978-0-19-958559-5 |edition=second |location=Oxford}}</ref>{{page needed|date=July 2024}} and Nisbett et al.<ref>{{Cite journal |last1=Nisbett |first1=Richard E. |last2=Aronson |first2=Joshua |last3=Blair |first3=Clancy |last4=Dickens |first4=William |last5=Flynn |first5=James |last6=Halpern |first6=Diane F. |last7=Turkheimer |first7=Eric |year=2012a |title=Intelligence: new findings and theoretical developments |url=http://people.virginia.edu/~ent3c/papers2/nisbett2012int.pdf |journal=American Psychologist |volume=67 |pages=130–159 |doi=10.1037/a0026699 |issn=0003-066X |pmid=22233090 |access-date=22 July 2013 |number=2 |archive-date=November 8, 2020 |archive-url=https://web.archive.org/web/20201108132004/http://people.virginia.edu/~ent3c/papers2/nisbett2012int.pdf}}</ref><ref>{{cite web |first=Dan |last=Willingham |title=The latest on intelligence |url=http://www.danielwillingham.com/1/post/2012/05/the-latest-on-intelligence.html |website=Daniel Willingham—Science & Education |date=10 May 2012}}</ref> all concluded that the gradual closing of the gap was a real phenomenon.

Flynn has commented that he never claimed that the Flynn effect has the same causes as observed differences in average IQ test performance between blacks and whites, but that it shows that environmental factors can create IQ differences of a magnitude similar to that gap.<ref>{{Cite journal |doi = 10.1016/j.intell.2010.05.001 |last1 = Flynn |first1 = J.R. |title = The spectacles through which I see the race and IQ debate |journal = Intelligence |volume = 38 |issue = 4 |pages = 363–66 |year = 2010 }}</ref> Wicherts ''et al''. had previously suggested a similar interpretation in a 2004 paper.<ref>{{cite journal |last1=Wicherts |first1=Jelte M. |last2=Dolan |first2=Conor V. |last3=Hessen |first3=David J. |last4=Oosterveld |first4=Paul |last5=van Baal |first5=G. Caroline M. |last6=Boomsma |first6=Dorret I. |last7=Span |first7=Mark M. |date=2004 |title=Are intelligence tests measurement invariant over time? Investigating the nature of the Flynn effect |journal=Intelligence |volume=32 |issue=5 |pages=509–537 |doi=10.1016/j.intell.2004.07.002 |quote=It appears therefore that the nature of the Flynn effect is qualitatively different from the nature of B–W differences in the United States. Each comparison of groups should be investigated separately. IQ gaps between cohorts do not teach us anything about IQ gaps between contemporary groups, except that each IQ gap should not be confused with real (i.e., latent) differences in intelligence.}}</ref> Flynn also argued that his findings undermine the so-called [[Spearman's hypothesis]], which hypothesized that differences in g factor are the major driver of the blacks-whites IQ gap.<ref>{{Cite journal |doi = 10.1037/0003-066X.54.1.5 |title = Searching for justice: the discovery of IQ gains over time |year = 1999 |last1 = Flynn |first1 = J.R. |journal = American Psychologist |volume=54| pages = 5–9 |url = http://www.stat.columbia.edu/~gelman/stuff_for_blog/flynn.pdf |access-date = 26 October 2017 |archive-date = 25 June 2010 |archive-url = https://web.archive.org/web/20100625085640/http://www.stat.columbia.edu/~gelman/stuff_for_blog/flynn.pdf |url-status = live}}</ref>