Tag Archives: Flynn Effect

An acceleration of cognitive decline?

26 Jun

Here a disturbing finding published in the most recent issue of the journal Intelligence, I have underlined the key sentence :

The cohort process of cognitive aging is a contested topic in population research. The literature is largely in disagreement over how and why inter-cohort trends in cognitive aging occur in the United States. This paper examines significant trends in the rate of cognitive decline and conceptualizes the role of the depression trajectory as a late life course process that accelerates cognitive aging at the individual and population level. To this end, I draw my study sample from the Health and Retirement Study (N = 24,678) and use aging-vector models as an extension of parallel-process latent growth modeling to analyze repeated measures of cognition and depression. Findings show the acceleration of cognitive decline (“negative” Flynn Effect) and worsening of depression risk for recent cohorts. The upward trends in depression account for significant acceleration in cognitive decline among later cohorts, thus providing a new insight into sociogenic population dynamics of cognitive aging.

From the body of the paper:

Taken together, the findings of the study strongly support the “negative” Flynn Effect on cognitive aging (Alwin, 2008). That is, later cohorts not only perform cognitive tasks more poorly, but also experience a faster rate of cognitive decline. As a result, considerable intercohort gaps occur particularly in old age. Further, the present study shows that the acceleration of cognitive decline is largely driven by depression symptomatology that concurrently evolves in late life, rather than by differences in cognitive reserves during adulthood (e.g., socioeconomic environments). Thus, the negative Flynn Effect is not necessarily paradoxical with regard to a continuous increase in educational attainment, which does not significantly predict the rate of cognitive decline. In contrast, depression risk in later life have significant impacts on cognitive decline at the individual and population levels. The results show that individuals develop an average of 1 to 2 additional depression symptoms in late life. Because later cohorts, particularly Non-Hispanic Blacks and Hispanics, are at higher risk of developing depression symptoms, their exposure to cognitive risk factors should be of public health concern.

James Flynn on the Flynn Effect

24 Oct

I showed this video to my doctoral students last week. It’s a nice summary of Flynn’s work. I regard the Flynn Effect as one of the most important discoveries, a greatest mysteries, of scientific psychology.

Special brag point: I am the author of the study he mentions on Ohio school examinations.

Are our brains getting bigger?

17 Feb

A paper in Learning and Individual Differences:

“Secular increases in brain mass over nearly a century have been noted for both males and females in the UK and Germany. It has been argued that such trends may be associated with the Flynn effect. The IQ gain predicted on the basis of these trends is 0.19 and 0.08 points per decade for UK, and 0.2 and 0.15 points per decade for German males and females respectively, indicating a small contribution to the Fullscale IQ trends in these countries (2.95% of the German decadal gain and 12.73% of the UK gain). There is also a sex difference in the rates of brain mass gain in both countries, favoring males. Temporal correlations between the secular trend in UK brain mass and European Flynn effects on Fullscale IQ, Crystallized, Fluid and Spatial abilities reveal correlations ranging from 0.751 in the case of Fluid ability to 0.761 in the case of Crystallized ability. The brain mass increase may be an imperfect proxy for changes in specific neuroanatomical structures important for IQ gains. Its small contribution to these gains is also consistent with the influence of other contributing factors. Increasing brain mass is predicted by the life history model of the Flynn effect as it suggests increased somatic effort allocation into bioenergetically expensive cortical real estate facilitating the development of specialized cognitive abilities.”


James Flynn: Are we getting smarter?

25 Sep

Here is an interview with James Flynn as part of the promotion for his book Are We Getting Smarter?: Rising IQ in the Twenty-First Century. Flynn is most famous for his discovery of what is now called the Flynn Effect, the observed substantial increase in IQ scores over time.


[Full disclosure: My research is cited on page 15 of this book]

Dementia rate falls in Denmark, England and Wales

17 Jul

Good news. Gina Kolata reports in the New York Times that two studies, one conducted in England and Wales, the other in Denmark have found falling rates of Dementia.

Why has the rate of dementia declined? One interesting possibility is the Flynn Effect, the observation that average IQ scores have risen substantially over time. IQ and dementia are inversely correlated, in other words the higher your IQ the lower your risk of dementia. Other explanations might be better health and better education, which also are correlated with lower dementia risk.

However, some caution is in order, the increase in obesity and type II diabetes we have observed in recent decades may counteract this positive trend as the population ages.

%d bloggers like this: