Freitag, 25. Dezember 2015

It's getting bigger all the time: Estimating the Flynn effect from secular brain mass increases in Britain and Germany

It's getting bigger all the time: Estimating the Flynn effect from secular brain mass increases in Britain and Germany
Michael A. Woodley of Menie, Mateo A. Peñaherrera, Heitor B.F. Fernandes, David Becker, James R. Flynn (2016)
Learning and Individual Differences


Highlights

Secular increases in brain mass are quantified in two countries (UK and Germany).
In the UK, brain mass increased by 52 g for males and 23 g for females over 80 years.
In Germany the increase was 73.16 g for males and 52.27 g for females over 99 years.
In terms of IQ, the UK gain = 0.19 and 0.08 points per decade for males and females.
In Germany, the IQ gain = 0.2 and 0.15 points per decade for males and females.

Abstract


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.

Mittwoch, 23. Dezember 2015

Fröhliche Weihnachten! Merry Christmas!



Viggo Johansen

Wissenschaft: Epistemische Rationalität

Heiner Rindermann: Zunächst einmal ist es die Aufgabe der Wissenschaft, wahre Aussagen zu formulieren, wahre und neue, also Erkenntnis zu schaffen und diese weiterzugeben. Wer was warum dazu assoziiert, ist aus der Perspektive epistemischer Rationalität irrelevant. Auch ist unwichtig, ob eine angenommene Übereinstimmung oder Nichtübereinstimmung mit Weltanschauungen vorliegt. Wenn man nach der Farbe fragt, ist die Größe irrelevant. Aussagen sind auf ihren empirischen Gehalt, auf ihre Übereinstimmung mit der Wirklichkeit, auf ihre Logik und Kohärenz mit anderen bestätigten Aussagen hin zu überprüfen. Gerade bei „heißen“, „politischen“, „umstrittenen“ und „historisch belasteten“ Themen ist es notwendig, sich im Denken zu orientieren. 2010 habe ich versucht, dies so zu beschreiben: 
„Unter epistemischer Rationalität ist eine explizit normative Dimension richtigen Denkens zu verstehen, eine Fähigkeit und Bereitschaft, das eigene und fremde Denken auf Wahrheit zu orientieren. Probleme werden als kognitiv lösbare Fragestellungen und nicht als durch Intuition oder Übernahme traditioneller Antworten abkürzbare Fragen, als durch Gewalt, autoritative Entscheidung oder durch Zwangsmaßnahmen zu bewältigende Hindernisse verstanden. Rationalität fordert den Einsatz von Denken, Intelligenz und Wissen zur Lösung von Problemen. Das eigene Denken wird unter den Vorbehalt notwendiger Richtigkeit, Begründung und Argumentation gestellt und ist prinzipiell durch Hinweis auf diese und überzeugendere Alternativen einer Änderung möglich. In Interaktion mit anderen oder sich selbst wird im rationalen Denken eine argumentative Haltung eingenommen, die gute Gründe, logische Kriterien wie Widerspruchsfreiheit und empirische Belege gelten lässt, nur diese und nichts anderes, nicht Überreden, Macht oder Ansehen der Person oder andere außerargumentative Kriterien. In epistemischer Interaktion, sei sie persönlich oder nicht persönlich, wird eine angemessen präzise, verständliche und inhaltsangemessene Sprache bis zur Sprache der Mathematik verwendet.“
Gerade bei heiklen Themen ist an den Kriterien der Vernünftigkeit und der Argumentativität festzuhalten. Hierfür ist auch eine aufmerksame, wenn notwendig kritische Leserschaft hilfreich, die Anregungen, Alternativen und Kritik formuliert, sich dabei aber auch selbst an Kriterien der Vernünftigkeit und der Argumentativität orientiert.

Dienstag, 22. Dezember 2015

Effect of smoking on physical and cognitive capability in later life: a multicohort study using observational and genetic approaches


Teri-Louise North, Tom M Palmer, Sarah J Lewis, Rachel Cooper, Chris Power, Alison Pattie, John M Starr, Ian J Deary, Richard M Martin, Avan Aihie Sayer, Meena Kumari, Cyrus Cooper, Mika Kivimaki, Diana Kuh, Yoav Ben-Shlomo, Ian N M Day (2015)


Objectives The observed associations between smoking and functional measures at older ages are vulnerable to bias and confounding. Mendelian randomisation (MR) uses genotype as an instrumental variable to estimate unconfounded causal associations. We conducted a meta-analysis of the observational associations and implemented an MR approach using the smoking-related single nucleotide polymorphism rs16969968 to explore their causal nature.

Setting 9 British cohorts belonging to the HALCyon collaboration.

Participants Individual participant data on N=26 692 individuals of European ancestry (N from earliest phase analysed per study) of mean ages 50–79 years were available for inclusion in observational meta-analyses of the primary outcomes.

Primary outcomes Physical capability, cognitive capability and cognitive decline. The smoking exposures were cigarettes per day, current versus ex-smoker, current versus never smoker and ever versus never smoker.

Results In observational analyses current and ever smoking were generally associated with poorer physical and cognitive capability. For example, current smokers had a general fluid cognition score which was 0.17 z-score units (95% CI −0.221 to −0.124) lower than ex-smokers in cross-sectional analyses. Current smokers had a walk speed which was 0.25 z-score units lower than never smokers (95% CI −0.338 to −0.170). An MR instrumental variable approach for current versus ex-smoker and number of cigarettes smoked per day produced CIs which neither confirmed nor refuted the observational estimates. The number of genetic associations stratified by smoking status were consistent with type I error.

Conclusions Our observational analysis supports the hypothesis that smoking is detrimental to physical and cognitive capability. Further studies are needed for a suitably powered MR approach.

Donnerstag, 3. Dezember 2015

Gender Differences in Subjective Well-Being and Their Relationships with Gender Equality

Gender Differences in Subjective Well-Being and Their Relationships with Gender Equality
Gerhard Meisenberg & Michael A. Woodley (2015)


Abstract

Although most surveys of happiness and general life satisfaction find only small differences between men and women, women report slightly higher subjective well-being than men in some countries, and slightly lower subjective well-being in others. The present study investigates the social and cultural conditions that favor higher female relative to male happiness and life satisfaction. Results from more than 90 countries represented in the World Values Survey show that conditions associated with a high level of female relative to male happiness and life satisfaction include a high proportion of Muslims in the country, a low proportion of Catholics, and absence of communist history. Among indicators of gender equality, a low rate of female non-agricultural employment is associated with higher female-versus-male happiness and satisfaction. Differences in the rate of female non-agricultural employment explain part of the effects of communist history and prevailing religion. They may also explain the recent observation of declining female life satisfaction in the United States.

Are gifted adolescents more satisfied with their lives than their non-gifted peers?

Are gifted adolescents more satisfied with their lives than their non-gifted peers?
Sebastian Bergold, Linda Wirthwein, Detlef H. Rost, and Ricarda Steinmayr (2015)


Abstract

Studies investigating the life satisfaction of intellectually gifted and non-gifted students are scarce and often suffer from methodological shortcomings. We examined the life satisfaction of gifted and non-gifted adolescents using a rather unselected sample of N = 655 German high-school students (n = 75 gifted), adequate comparison groups of non-gifted students, and a clear definition of giftedness (general intelligence g > 2 SD above the mean). There was no difference in life satisfaction between gifted and non-gifted adolescents (d < |0.1|). Girls reported somewhat lower life satisfaction scores than boys (d = 0.24). However, this result was not specific to giftedness but was instead found across the entire sample. Thus, gifted girls were not found to be especially unsatisfied with their lives. Our findings support previous research showing that giftedness is not a risk factor for impaired psycho-social well-being of boys or girls.