Flynn effect

Harnad The Flynn effect occurs on modem IQ tests in modern societies it is interesting, but I don t see its bearing on the kind of question that Andy Whiten was raising. 

Jensen There is another Flynn effect, in the physical realm, and that s for height. There have been comparable increases in height over the same period. For example, J. M. Tanner (University of London) mentions that 10-year-old children today in London schools are four inches taller than they were 100 years ago. Since World War I there have been the same kinds of increases to about the same extent in standard deviation units. There are other parallels as well. For example, the correlations between different body measurements have remained the same over this time, despite the increase in height. And the differences between various national and ethnic groups that differ in height has continued to exist. 

Jensen This is especially interesting because the heritability of height is 0.95. This shows the independence of the heritability and the mean value. Now an interesting question is, why have psychologists got so worked up over the Flynn effect for IQ, while there s been no great excitement about this Flynn effect for height ... 

Much the same applies to the rise in IQ levels over time—the so-called Flynn effect. Clearly, it is implausible that this has a genetic origin—the gene pool cannot change that quickly. However, we remain in doubt over just which aspects of the environment have been responsible. Turkheimer (1991) made the point that it is a mistake to assume that effects on the level of a trait are necessarily different from... 

In this subsection I will deal with the effects on IQ of socioeconomic class (the Turkheimer study), and in the next subsection with the Flynn Effect. These are two important new developments that concern individual IQ and need to be discussed in detail. This whole section is the first part of myth-debunking. The second part appears in the final chapter and deals with an array of other myths that are more general. 

This is the Flynn effect, named after James R. Flynn, the New Zealand psychologist who first brought the phenomenon to everyone s attention.35 Within a few years it was further discovered that the effect is also occurring in 14 nations around the world.36 The number of nations has now grown to 23T... 

The first study to document the Flynn effect in a rural area of a developing country (Kenya) was reported in 2003.38 From 1984 to 1998, the Raven s IQ score in that rural district increased 4.5 points. The Raven s (known as Raven s Standard Progressive Matrices) is a widely-used, mainly culture-free, IQ test involving analogies of geometric shapes. Results from a study on the Caribbean island of Dominica were reported in 2005.39 In this study a Flynn-effect increase in Raven s IQ score of 17 to 19 points apparently occurred over a period of 37 years. 

Whatever the reasons for it, everyone agrees the Flynn effect is a real phenomenon. And some of its apparent implications are startling. If IQs have been rising with each generation, then... 

In short, the existence of the Flynn effect seriously weakens the usefulness of IQ tests. For example, IQ tests are used in public policy directives to identify children with mental retardation. But many children who are labeled mentally retarded by IQ test performance today would not have been so labeled 50 years ago. A child with an IQ tag of 70 today would have an IQ score 50 years ago of 86.5 in its own cohort and be out of the mentally retarded group. In parallel, the labeling of some criminals as mentally retarded, crucial for sentencing purposes, can depend on whether an older or newer version of an IQ test is used to determine the label.42... 

The Turkheimer study discussed in chapter 10 pointed out that correlations between heredity or environment and IQ are dependent on socioeconomic class, with environment contributing nearly all the variance for the lower socioeconomic class.81 The study shows us that the contributions of heredity and environment to variance of IQ scores depend on the socioeconomic class of the population tested. The Flynn effect shows us that distributions of IQ scores are artifacts of test construction and depend on the generation tested. Both effects are of great importance for social policy. 

Meisenberg, G., Lawless, E., Lambert, E., Newton, A. (2005). The Flynn effect in the Caribbean generational change of cognitive test performance in Dominica. Mankind. Q, 46 29—69. 

Russell, E. W. (2007). Commentary the Flynn effect revisited. Appl. Neuropsychol. 14 262—266. 

Flynn and Dickens [142] have translated the relaxation methods of fluid kinetics into terms applicable to solid phase thermogravimetry. The rate-determining variables such as temperature, pressure, gas flow rate, gas composition, radiant energy, electrical and magnetic fields are incremented in discrete steps or oscillated between extreme values and the effect on reaction rate determined. 

Phytoestrogens have also been shown to have behavioural effects in rodents including increases in sexual activity (Patisaul et al, 2001) and a reversal of sex-specific behaviours (Lund et al, 2001 Flynn et al, 2000). In rodents, the sexually dimorphic nucleus of the preoptic area (SDN-POA) is located in the hypothalamic region of the brain. This area of the brain controls... 

FLYNN K M, FERGUSON s A, DELCLOS K B, NEWBOLD R R (2000) Effects of genistein exposure on sexually diamorphic behaviors in rats. Toxicol Sci. 55 311-19. 

Data on safety have been obtained from in vitro as well as in vivo animal and human studies (see also Section 10.4). About 50 years ago, Australian farmers observed an infertility syndrome in sheep associated with the consumption of clover species (Bennets et al., 1946). The clover compounds shown to cause the infertility (genistein, daidzein, equol, biochanin A, formononetin) were members of the isoflavone family (Bradbury and White, 1951 Shutt and Braden, 1968), raising the question of whether soy might cause infertility in humans (see also Section 10.4.9). A variety of reports further supported adverse effects of isoflavones on animal reproductive systems (Santell et al., 1997 Flynn et al., 2000a,b). 

C. B. Lalor, G. L. Flynn, and N. Weiner. Formulation factors affecting release of drug from topical formulations. I. Effect of emulsion type upon in vitro delivery of ethyl p-aminobenzoate. J. Pharm. Sci. 83 1525-1528 (1994). 

J.-C. Tsai, M. J. Cappel, N. D. Weiner, G. L. Flynn, and J. Ferry. Solvent effects on the harvesting of stratum corneum from hairless mouse skin through adhesive tape stripping in vitro. Int. J. Pharm. 68 127-133 (1991). 

Gibson DR, Flynn NM McCarthy JJ (1999). Effectiveness of methadone treatment in reducing FlIV risk behaviour and HIV seroconversion among injecting drug users. AIDS, 13, 1807-18... 

Flynn and Stoneham [1970] were the first to suggest that diffusion of the light impurity atom is enhanced by symmetrically coupled vibrations. To incorporate this effect, which is called fluctuational barrier preparation, the authors have proposed to take into account the dependence of the tunneling matrix element on displacements of the heavy nuclei. This approach goes beyond the familiar Condon approximation. In this version of phonon-assisted tunneling, the phonon-dressed incoherent transitions are also induced by a suitable reduction in the barrier height via emission or absorption of phonons. 

Solvent deasphalting processes have not realized their maximum potential. With on-going improvements in energy efficiency, such processes would display its effects in a combination with other processes. Solvent deasphalting allows removal of sulfur and nitrogen compounds as well as metallic constituents by balancing yield with the desired feedstock properties (Figure 8-16) (Flynn et al., 1961 Ditman, 1973). 

Extensive investigations into the effects of flaxseed consumption, by mothers during gestation and lactation, on the offspring have been reported. Various effects in the offspring of rats fed flaxseed at levels between 5% and 40% have been observed (Collins et al., 2003 Flynn et al., 2003 Orcheson et al., 1998 Tou and Thompson, 1999 Tou et al., 1998, 1999 Ward et al., 2000, 2001a). 

Flynn, T.J., Collins, T.F.X., Sprando, R.L., Black, T.N., Ruggles, D.I., Wiesenfeld, P.W., and Babu, U.S. 2003. Developmental effects of serum from flaxseed-fed rats on cultured rat embryos. Food Chem Toxicol. 41, 835-840. 

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