IQ more variable than previously thought

It has generally been thought that IQ is fairly stable from the teen years onwards. Non-cognitive ability however has been seen as more malleable & this idea has featured in Jim Heckman's work especially since non-cognitive ability seems to be quite important for labour market outcomes. However based on this study it now seems that IQ varies much more than previously thought for teenagers. What is not clear is whether it can be actively increased by interventions.

Some interesting facts about intelligence

Eleven things you may not know about IQ

The importance of cognitive and social skills for the duration of unemployment

Verena Niepel
This paper studies how cognitive and social skills in childhood are related to the duration of unemployment in adolescence and early adulthood. I estimate a flexible proportional hazard rate model for the probability of making a transition from unemployment to employment during an individual's first unemployment spell. The analysis is based on British cohort data from the National Child Development Study. Results show that higher cognitive and social skills at the age of 7 are associated with an increased probability of finding employment, even when controlling for educational attainment. For men, these effects are mostly driven by individuals with low social skills. The results are robust to controlling for family background, parenting activities and school characteristics.

Smart boy wanted: longevity and intelligence

Economists are interested in the returns to cognitive ability. One fairly basic return is longevity: smarter people live longer. But why? An obvious explanation is that they make better choices, avoiding the Darwin Awards for example. A more specific hypothesis is that they cope better with adversity and hence live longer. Some experimental evidence is detailed here. Don't worry: it uses bees.

Risk Aversion, Impatience & Cognitive Ability

Are Risk Aversion and Impatience Related to Cognitive Ability?
Dohmen Thomas,Falk Armin,Huffman David

This paper investigates whether risk aversion and impatience are correlated with cognitive ability. We conduct incentive compatible choice experiments measuring risk aversion, and impatience over an annual time horizon, for a representative sample of roughly 1,000 German adults. A measure of cognitive ability is provided by two submodules of one of the most widely used IQ tests. Interviews are conducted in subjects'' own homes. We find that lower cognitive ability is associated with greater risk aversion, and more pronounced impatience. These relationships are statistically and economically significant, and robust to controlling for personal characteristics, educational attainment, income, and measures of liquidity constraints.
http://edocs.ub.unimaas.nl/loader/file.asp?id=1445

The Labor Market Returns to Cognitive and Noncognitive Ability: Evidence from the Swedish Enlistment

Lindqvist, Erik (Research Institute of Industrial Economics (IFN))
Westman, Roine (New York University)

IFN Working Paper No. 794, 2009

We use data from the military enlistment for a large representative sample of Swedish men to assess the importance of cognitive and noncognitive ability for labor market outcomes. The measure of noncognitive ability is based on a personal interview conducted by a psychologist. Unlike survey-based measures of noncognitive ability, this measure is a substantially stronger predictor of labor market outcomes than cognitive ability. In particular, we find strong evidence that men who fare badly in the labor market in the sense of long-term unemployment or low annual earnings lack noncognitive but not cognitive ability. We point to a technological explanation for this result. Noncognitive ability is an important determinant of productivity irrespective of occupation or ability level, though it seems to be of particular importance for workers in a managerial position. In contrast, cognitive ability is valuable only for men in qualified occupations. As a result, noncognitive ability is more important for men at the verge of being priced out of the labor market.

Using Measures of Non-Cognitive Ability in Economics

Cognitive ability (as measured by test scores) only determines part of a person's success in the labour market. This came into sharp focus in the economics profession at the 2001 meeting of the American Economics Association. At this meeting a number of papers were presented about the importance of non-cognitive ability (also referred to by some authors as 'non-cognitive skills'). An example is Heckman and Rubinstein (2001) who mention non-cognitive skills such as "persistence, reliability and self-discipline". Most often though, the phrasing of "non-cognitive ability" is used, for example: Heckman, Stixrud and Urzua (JLE, 2006): "The Effects of Cognitive and Noncognitive Abilities on Labour Market Outcomes and Social Behavior."

Heckman and Rubinstein (2001) identified the importance of non-cognitive abilities with their observation that high school equivalency recipients earn less than high school graduates despite the fact that the high school equivalency recipients are smarter. They attribute this to the negative non-cognitive attributes of equivalency recipients originally dropping out. Their conclusion is that individuals with higher amounts of persistence and self-discipline may be more likely to attain academic qualifications.

In relation to further evidence, Heckman, Stixrud and Urzua (2006) model the influence of young individuals' cognitive and non-cognitive abilities on schooling and earnings. They find that better non-cognitive abilities lead to more schooling, but also have an earnings return over and above this. Kern and Friedman (2008) de-compose (overall) conscientiousness into a range of non-cognitive abilities, including persistence, industriousness, organisation and discipline (read previous blog discussion on this here).

The trait of conscientiousness is taken from the "Big Five" set of personality characteristics. Kyllonen, Walters and Kaufman (2005) review the literature on noncognitive constructs (such as the "Big Five"), and conclude with a discussion of how non-cognitive constructs (or personality factors) might be used in admissions and guidance applications for graduate education (read previous blog discussion on this here).

Braakmann (2009) has used the German Socio-Economic Panel to show that differences in various non-cognitive traits, specifically the Big Five, contribute to gender inequalities in wages and employment (this was previously mentioned on the blog here). Mueller and Plug (2004) shows that the labour market values conscientiousness and openness to experience for women (previous discussion on the blog here --- in relation to non-cognitive personality, education and earnings).

Kyllonen (2008) is perhaps the most detailed assessment of how to measure non-cognitive abilities; he associates the non-cognitive abilities shown below with the "Big Five" personality traits. Kyllonen is based at the Princeton Educational Testing Service (ETS) and put forward the framework below ("Enhancing Noncognitive Skills to Boost Academic Achievement") at a 2008 Washington conference entitled 'Educational Testing in America: State Assessments, Achievement Gaps, National Policy and Innovations'.