X-Message-Number: 27611
Date: Sun, 12 Feb 2006 19:02:33 -0800 (PST)
From: Doug Skrecky <>
Subject: The Flynn effect

[For unknown reasons, people are getting gradually becoming smarter across
the generations. This amounts an increase of about 3.3 IQ points per
decade. This change may be partly responsible for the comparatively
rapid technological advances that have been made in the last
century. IHMO, whatever chances the present generation has of eventually
living well beyond the traditional 3 score and ten, may well devolve to
the Flynn effect, as it is called.]

Am Psychol. 2003 Oct;58(10):778-90.
The Flynn effect and U.S. policies: the impact of rising IQ scores on
American society via mental retardation diagnoses.
    Over the last century, IQ scores have been steadily rising, a
phenomenon dubbed the Flynn effect. Because of the Flynn effect, IQ tests
are periodically renormed, making them harder. Given that eligibility for
mental retardation (MR) services relies heavily on IQ scores, renormed
tests could have a significant impact on MR placements. In longitudinal IQ
records from 9 sites around the country, students in the borderline and
mild MR range lost an average of 5.6 points when retested on a renormed
test and were more likely to be classified MR compared with peers
retested on the same test. The magnitude of the effect is large and
affects national policies on education, social security, the death
penalty, and the military. This paper reports the perceptions of
professionals as they relate to IQ score fluctuations in normal,
borderline, and/or MR populations.

Psychol Sci. 2003 May;14(3):215-9.
IQ on the rise: the Flynn effect in rural Kenyan children.
    Multiple studies have documented significant IQ gains over time, a
phenomenon labeled the Flynn effect. Data from 20 industrialized nations
show massive IQ gains over time, most notably in culturally reduced tests
like the Raven's Progressive Matrices. To our knowledge, however, this is
the first study to document the Flynn effect in a rural area of a
developing country. Data for this project were collected during two large
studies in Embu, Kenya, in 1984 and 1998. Results strongly support a
Flynn effect over this 14-year period, with the most significant gains
found in Raven's matrices. Previously hypothesized explanations (e.g.,
improved nutrition; increased environmental complexity; and family,
parental, school, and methodological factors) for the Flynn effect are
evaluated for their relevance in this community, and other potential
factors are reviewed. The hypotheses that resonate best with our findings
are those related to parents' literacy, family structure, and children's
nutrition and health.

Psychol Rev. 2002 Oct;109(4):759-63; discussion 764-71.
Expanding variance and the case of historical changes in IQ means: a
critique of Dickens and Flynn (2001).
    The Flynn effect is the rise in mean IQ scores during the 20th
century, amounting to about 0.33 IQ points per year. Many theoretical
explanations have been proposed, though none are universally
accepted. W. Dickens and J. R. Flynn's (2001) new approach explains the
large IQ changes by means of recursive models of IQ growth. A salient
feature of their models is that IQ phenotypes and their supportive
environments are correlated; in addition, environmental effects can
rebound on phenotypic IQ to increase or lower IQ. In this critique, the
authors examine an empirical challenge to their models, which typically
imply large changes in IQ variance. However, the historical rise in IQ
mean level has not been accompanied by substantial variance changes, a
finding inconsistent with the properties of the proposed model.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=27611