#IQ2014 second day so far

 

Numerical ability is the gateway into STEM success finds E.Stern at ETH Zurich, looking at engineering and maths/physics students, average IQ roughly 120. Sample size still small, will report when up to 200 subjects.

Paulette Flore (P.C.Flore@tilburgunivesity.edu) looked at stereotype threat on girls’ test performance. She finds that the effect is at best slight, and probably due to publication bias. 26 relevant papers found total n=3760 and although a positive effect was initially found the Hedges’ g –0.22 effect size was very small. The power of most studies was low, below .4 with one exception at .8

Georg Kramer (georg.kramer@phst.at) finds that a general mental ability test plus a structured interview were a good predictor of academic achievement in college bachelor degree admission, predicting grade point average every year, and did better  in predicting final grades than the 3rd year grade point average.

#IQ2014 first day

 

This is a jumble, just to prove I arrive at the conference.

Ian Deary presented an extraordinary range of his work covering over 30 years showing how (rewinding) he came to write particular papers and then how the new generation of younger colleagues in his department “remixed” them with better techniques and data sets.

In words I will not repeat to sensitive readers he spoke of the power of massive samples, or better still, entire populations, to silence carping critics who claim that psychometricians always use small samples. I will try to get further detail from the very full presentation.

Gignac presented data on digit span, formerly the ugly duckling of intelligence assessment, and saved only by Jensen from being dropped from the Wechsler. Giofre put in a plea for sensitive scoring systems which incorporated partially correct scores when studying working memory.

In a very big meta-analysis Tim Bates showed that social class interacts with intelligence to some extent in US samples, but not in other parts of the world. It suggests that the much quoted Turkheimer (2003) is something of an outlier in the US funnel plot, but there is a US/rest of world difference, though hard to be sure why, possibly less supportive welfare environment for poor Americans.

Latvala showed that parent’s anti-social behaviour did not have behavioural effect on offspring. Effects seemed to be primarily genetic.

This morning we had a keynote address by Terrie Moffitt and Avshalom Caspi on how one identifies the children who will later turn out to be ultra-high cost individuals in society, using welfare, health service and getting into trouble with the law. With 81% efficiency such children can be spotted at age 3. However, whether anything can be done about it is unclear, though training in self-control seems to be a possible avenue of intervention.

 

 

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Attending conferences: a test of intelligence?

 

The cognitive load imposed by attending a conference is considerable. One must book the conference, then the hotel, calculating whether you will need an extra night before or after the conference. Then you must book flights so as to arrive in good time before, and leave in good time afterwards. If necessary, you must book a car, taxi or a train to get from the airport to the conference hotel, allowing a time for the transfer. If these arrangement mean you stray into another day, then the dates must be coordinated again. The plane must not leave the airport before the car has been returned. It is almost as hard as digits backwards.

You must also ensure you have the necessary currency, passports, travel tickets, and the correct clothing. It is prudent to carry a universal power adapter, extra batteries for devices and a satnav for the car.

Is it any wonder that most people stay at home and read the abstracts afterwards? However, conferences sometimes engender the sensation that something is being achieved, that a contribution is being made to knowledge.

The notion of being a contributor to society runs deep with many citizens, and the distinction between contributors and non-contributors is both interesting and sometimes upsetting. The very young and the very old are understood to contribute less at those ages, though they will generally have contributed much over the bulk of their lifetimes. Setting aside age differences, what distinguishes contributors from non-contributors?

One of the keynote addresses at #IQ2014 looks at this contentious issue.

In “Early childhood origins of an ultra-high-cost segment of the population” Keynote Terrie E. Moffitt of Duke University and Avshalom Caspi of King’s College London
(terrie.moffitt@duke.edu; avshalom.caspi@duke.edu) say:

Worldwide, the population is aging and children are becoming rare. Nations increasingly view young people as a valuable resource for the economic and social wellbeing of whole societies. There is intense interest in early interventions to help all children achieve their potential. However, evidence is lacking to identify which
childhood risk factors to target, to yield the best return on investment.
Method: We used data from the Dunedin Study, a four-decade longitudinal study of a birth cohort of 1000 New Zealanders. We examined risk factors in childhood and measures of social, health, and economic costs in adulthood.
Results: Adult social and economic outcomes fit the Pareto principle: 20% of the cohort accounted for approximately 80% of every outcome: the cohort’s months of social welfare benefits, years of absent-father childrearing, pack-years of cigarette smoking, hospital admissions, pharmacy prescription fills, criminal court convictions, and injury-related insurance claims. Moreover, high-cost individuals with one problem outcome tended to also have multiple problem outcomes. An ultra-high-cost sub-segment of the cohort was identified who accounted for 80% of multiple problems.
Risk factors measured in childhood that characterized this ultra-high-cost group were: low family socio-economic status, child maltreatment, low self-control, and low IQ. Effect sizes were very large. Predictive analyses showed that together, SES, maltreatment, self-control, and IQ measured in the first decade of life were able to predict 80% of the individuals who are using 80% of multiple costly services. We developed an index of the integrity of a child’s brain at age three years. This age-3 brain-integrity index was a strong predictor of the cohort members who four decades later became members of the ultra-high-cost population segment.
Implications: Much research has shown that childhood risk ‘X’ can predict poor adult outcome ‘Y’, but modest effect sizes discourage translation of findings into targeted childhood interventions. This study illustrates that the vast bulk of a nation’s social services, crime control, and health-care are expended on a relatively small population segment.
During early childhood, this population segment is characterized by a small set of risk factors: low SES, child maltreatment, low self-control, low IQ, and poor brain integrity. Reducing these factors may bring surprisingly good return on investment.

I will give you more details from the conference, that is, if I manage to get myself there successfully.

Job opportunities in intelligence research

 

I don’t know how many jobs are ever offered directly to students who want to do research on intelligence, but currently they must be few and far between. However, here are some opportunities for students who already have a Master’s degree.

The Centre for Cognitive Ageing and Cognitive Epidemiology in Edinburgh is offering 3-year fully-funded PhD studentships commencing September 2015.
The studentships are in cognitive ageing/cognitive epidemiology or experimental and human neuroscience and the ageing brain. A number of projects spanning the Centre's 6 research groups are available:
- Cognitive Epidemiology
- Human cognitive ageing: Individual differences
- Human cognitive ageing: Human cognitive neuropsychology
- Mechanisms of cognitive ageing
- Genetics, genomics and epigenetics: Experimental, pathway and statistical analysis in brain ageing
- Human and animal brain imaging

Further information and an application form is available on the CCACE website: www.ccace.ed.ac.uk.
The deadline is Friday 30th January 2015; interviews will be held in March 2015. Candidates must already hold a Master's degree in a relevant field.

If your own department is looking for intelligence researchers, please send me the details so I can circulate them as well.

Listen to her play

 

To Holy Trinity Church last night, the Cathedral of the Arts and Crafts movement , to listen to the Carol Service, the celebration somewhat perturbed by the ministrations of a Sky TV crew such that the opening address was a safety announcement by an AFM (assistant floor manager), providing the most lowering introduction to Christmas imaginable, but the mood lifted quickly to the finely detailed rafters with the opening carol.

Then a feast of performers: Actors Robert Lindsay, Sally Phillips (Bridget Jones’ Diary), James Norton; the Freshfields Choir and CMS Chorale, that ensemble blessed with one soprano with a clarion descant. I suggested to her later that she get an agent, but her husband said she already sang just for him and he did not want his domestic arrangements perturbed, and who could blame him.

Then the astonishing Katherine Jenkins, OBE, whose slight form packs a mighty voice. She delivered a great Leonard Cohen Hallelujah; a beautiful Silent Night; and a Placide Cappeau/Adolphe-Charles Adam O Holy Night which would have gained approbation from anyone who ever sung in the Welsh valleys. An ex-teacher before her first record contract, she paid particular attention to the kids in the Colvestone Primary School Choir, beneficiaries of the The Prince’s Foundation for Children and the Arts http://www.childrenandarts.org.uk/

I mean no disrespect to the aforementioned great performers, but let me continue as I had intended.

Then the star: This lady rocks. Just off the plane with her violin that morning at 3 am from a Sony recording session in Poland, Jennifer Pike gave a commanding performance of transformative power. Her playing of Vaughan William’s The Lark Ascending was a masterpiece. Power, precision and infinite tenderness from the first note.

She closes her eyes while playing, she says, because she wants to see the form of the music in her mind, visualising where it must move to next. From time to time she looks at the faces in the audience, and seeing them changes her performance, making it different and more fun than the empty studio she was recording in the day before. She doesn’t consciously aim for a particular style, though Menuhin is always in her mind, not surprising given that she won the Menuhin International Violin Competition at the age of 12.

And so to bed.

Link for “Are bright people normal” paper

 

http://drjamesthompson.blogspot.co.uk/2014/12/are-bright-people-normal.html

Last week I posted about normal brightness, but did not at that time have a link to the actual paper. This is a legitimate open source link. You can read it without a publisher visiting you at home and disembowelling you. Well, I cannot exclude the possibility that they will do so out of sheer devilment, but your grieving family will probably win the case against them.

http://dx.doi.org/10.1016/j.intell.2014.11.005

Cognitive gaps between immigrants and natives

 

#IQ2014

Here is one of the posters from the ISIR conference which begins later this week. I will post up the full paper at a later date, but of course the idea of a poster is to get you to talk with the authors, ideally over coffee, but in this case more easily by commenting here on the blog.

https://drive.google.com/file/d/0B3c4TxciNeJZN2pfcXl1Z0MxMm8/view?usp=sharing

Jobs: IQ tests versus interviews

 

In a place of constrained avian discourse I got into a debate about intelligence testing.  One suggestion made to me was:  Psychologists' naive interpretations of "intelligence" have been doing social harm for 80 years. Please stop it.

I replied: Ignoring intelligence measures is not without harm.

Another  questioner asked: I'd love an example of intelligence measures helping society in an equitable way.

I replied: Probably best example job selection, more equitable than interviews.

Anyway, that is enough background to understand the next step, which is about disclosing the material upon which one relies for a particular opinion. There are often testy exchanges about this. Some people get offended if told, in the middle of an argument, You should read the following papers. In my view academic debates should be punctuated by long moments of silence, broken only by pages turning as the combatants do the necessary reading. Show me your references is often a valid challenge. Not always, because there are some general points and personal observations which can be given without chapter and verse, but the ideal is that we should back up our opinions with relevant publications. The other reason for checking references is that memory is fallible, and although people may remember the general shape of the results, relevant details will have been forgotten.

I made my remark about job selection based on something I had read a decade ago in Ian Deary’s Intelligence: A very short introduction Oxford University Press, 2001. Here is the reference:

Schmidt, FL & JE Hunter (1998) The validity and utility of selection methods in personnel psychology: practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124, 262-74.

 

These authors had asked the simple question: is it worthwhile for an employer to select people for a job on the basis of, among other things, a test of general mental ability? The authors then looked at the correlation between the selection measures and eventual productivity, showing that intelligence test results were far better than interviews. Specifically, using test results will result in higher productivity, using an interview alone would lose three quarters of that gain. So, my main point about IQ tests being more fair than interviews can be validated by a good meta-analytic study. It was this paper which I had in mind when I made that remark. Incidentally, intelligence tests were originally seen as liberators, allowing bright working class children to rise through the system, despite not having been coached by private schools. Interviews were recognised to be rituals in which school ties and other social markers could be displayed so as to get unfair advantage.

There are other good predictors, though many take longer, and are thus more costly. For example, work sample tests are the best predictor, but since they involve a detailed evaluation of how each applicant does the sample job, they are time consuming, and difficult to arrange for some jobs. Highly structured job interviews do well (I had forgotten this) but unfortunately unstructured interviews are far more common, and far less valuable, so interviews are usually poor overall. Reference checks are not much help (perhaps because references are all much the same). Years of education is a very poor predictor, which is interesting considering it is often used as a surrogate measure of social advantage in educational research.

Compared with all these, intelligence testing can be used for all jobs, is a good predictor, and is relatively quick and cheap. The more complex the job, the better the prediction. Hunter and Schmidt found intelligence tests to be the best selection measure, and the 18 others only supplements. In terms of the multiple regression, after IQ the integrity test added 27% predictive power, a work sample or a structured interview another 24%. IQ plus integrity test is a good basic combination for an efficient result.

What did I not remember? That which I did not know when I first read the reference a decade ago. I did not know the high regard in which Schmidt and Hunter are held by methodologists. I recalled the highlights of their work as quoted in Deary’s book, rather than their names. The major consequence of their careful work was to establish a benchmark for excellence in meta-analysis.

In their 2004 paper General Mental Ability in the World of Work: Occupational Attainment and Job Performance Table 1 gives you the general ability scores of enlisted men by their civilian occupations. An instructive list which shows the intellectual demands of occupations, and also serves as a sad roll call of all the jobs that were part of an industrial society and are no more.

http://people.wku.edu/richard.miller/GMA.pdf

Their magnum opus is this fearsome tome:

Methods of Meta-Analysis: Correcting Error and Bias in Research Findings – 2004 by John E. Hunter (Author, Editor), Frank L. Schmidt (Author) Sage.

Make sure you give it as suggested reading to intelligence denigrationists.

Advance warning: Austrian intelligence drops

 

This year’s International Society for Intelligence Research meeting 12-14 December will be in Austria, and it is anyone’s guess what the influx of intelligence researchers will do, however briefly, for the intellectual levels of that nation. At the very least the need to congregate in the same place and at the same time will test some basic skills, and embarrassing lapses will be gleefully published, assuming I make it to the correct place in time to record them.

There will be much to report on, and I hope to be able to do that on your behalf. On past performance it is almost impossible to cover a conference whilst also taking part. It is a once-a-year chance to meet researchers and find out what they are working on, to hear argument and counter argument, and to watch scholars of entirely contrary positions chat over coffee. Given the very high demands on my limited channel capacity, I will probably report twice: once very briefly from the conference, and then at a more length subsequently when authors have sent me their papers.

In a welcome nod to modernity the organisers have agreed a Twitter tag

#IQ2014

I will try to get this noticed by giving you Twitter highlights, and hope you will assist me in this project so as to spread the word about the conference.

The program is shown below. The main topics are: Memory and cognitive bias; genetics; methods and psychometrics; intelligence and life outcomes; intellectual growth; neuroscience; education; creativity.

http://www.isironline.org/wp-content/uploads/2014/12/ISIR2014-Conference-program-overview.pdf

If some topics are of particular interest to you, please let me know and I will mark them for special attention.

You will see many familiar names (familiar to loyal readers anyway) and also new names of researchers who are presenting for the first time. If you have students who would like to find fame and fortune they should apply for the ISIR best graduate student presentation award given to the graduate student who gives the best presentation and includes a $500 cash award.

In the best traditions of transparency, I am sometimes on the assessment panel, and sometimes not, so a coffee and an Austrian pastry could be a good investment, or not.

Are bright people normal?

 

Every now and then I hear stories about us humans being far too dull to have done anything interesting in the past, and that the Pyramids or some such ancient government job creation scheme must have been the work of super-intelligent beings from outer space. Of course, this begs the question: by what process did these beings become super-intelligent?

However, in the way that, slightly to our surprise, we carry little bits of Neanderthal DNA and probably some early hominid adaptations to altitude and the like in our genomes, it might be the case that bright people carry bits of DNA of a sort not usually seen in common folk. For example, genius genes, genes for witty repartee and a gene for the intrinsic, uninstructed appreciation of Feynman diagrams.

In search of the miraculous, a group of researchers from the Plomin lab have analysed the Swedish Enlistment Battery test results of 3 million conscripts, from which they abstracted sibling and twins for analysis.

Nicholas G. Shakeshaft, Maciej Trzaskowski, Andrew McMillan, Eva Krapohl, Michael A. Simpson, Avi Reichenberg, Martin Cederlöf, Henrik Larsson, Paul Lichtenstein,Robert Plomin. Thinking positively: The genetics of high intelligence.
Intelligence 48 (2015) 123–132.

They say:

a key question is whether the genetic causes of high intelligence are qualitatively or quantitatively different from the normal distribution of intelligence. We report results from a sibling and twin study of high intelligence and its links with the normal distribution. We identified 360,000 sibling pairs and 9000 twin pairs from 3 million 18-year-old males with cognitive assessments administered as part of conscription to military service in Sweden between 1968 and 2010. We found that high intelligence is familial, heritable, and caused by the same genetic and environmental factors responsible for the normal distribution of intelligence. High intelligence is a good candidate for “positive genetics” — going beyond the negative effects of DNA sequence variation on disease and disorders to consider the positive end of the distribution of genetic effects.

So, normal.

But there is a little more to this than meets the eye. Very low intelligence is often caused by some “negative” genes which “interfere with the working of a naturally good brain, much as a bit of dirt may cause a first-rate chronometer to keep worse time than an ordinary watch ”. It is not impossible that a handful of “positive” booster genes are responsible for creating genius minds, even in Sweden.

In quantitative genetic studies (Nichols, 1984; Reichenberg et al., in preparation), a critical piece of evidence is that siblings of individuals with severe intellectual disability have an average IQ near 100, whereas siblings of those with mild intellectual disability have an average IQ of around 85, about one standard deviation below the population mean. In recent molecular genetic studies, rare non-inherited mutations appear to be a major source of severe intellectual disability
(Ellison, Rosenfeld, & Shaffer, 2013).

Naturally, given the big difference between familial and genetic retardation, then there might be a difference between normal wit and genius brightness. You will have noted the first part of the sentence is wrong, because familial retardation is also genetic, but “genetic” retardation is genetic plus genetic mutations. By the way, this also relates to presumed genetic differences in intelligence:

http://drjamesthompson.blogspot.co.uk/2014/03/what-does-iq-70-mean-for-black-and.html

Another option is that genius is caused by some special hothouse training, in which young children are taught chess moves day and night, with calculus at lunchtime. Such kids would show genius despite their genetics: an environmental effect due to family circumstances.

In this study the top 5% of the sample were considered bright. The refined readers of this blog may be allowed a superior snigger (a snigger is laugh in a half-suppressed, typically scornful way).

The sample comprised 3 million 18-year-old Swedish males. From these, 363,905 families were identified containing at least two conscripted male siblings born in Sweden. From each family, we selected one twin pair if present (the youngest, if the
family contained more than one pair); if there were no twins, we selected the two male siblings closest to one another in age (the youngest, again, if two such pairs had the same age difference).

The authors tried two different techniques in their data analysis, and each raise interesting issues. For example, if you dichotomise population into “Very bright” vs everyone else, then the very bright group will have reduced variance, and variance is what you need when you are conducting analyses of variance.

The analysis which in my view has most power is DeFries–Fulker (DF) extremes analysis. Regression to the mean is a fascinating measure which has a strong genetic explanation and only a weak environmental explanation. Indeed, where two siblings are brought up in the same family, as is the case here, there is no really credible environmental explanation as to why one of a sibling pair should regress more to the mean than another. They have the same parents, the same house full or not full of books, and often go to the same schools.

(I will try to come back to this elsewhere, because genetic regression to the mean raises the question as to which mean you regress to: the national mean, or the mean for your genetic group?)

The dichotomous data – high intelligence versus the rest of the distribution – can be analysed by comparing the degree of concordance for MZ and DZ twins, and for non-twin siblings. Here, we used probandwise concordance: the proportion of  “affected” individuals (i.e., those with a stanine score of 9, in this case) who have a twin or sibling who is also affected. This method indicates morbidity risk, i.e., the probability that a sibling or co-twin of someone in the high-intelligence group will also be in that group

As shown in Fig. 3, MZ co-twins of those in the high intelligence group regress to the population mean to a much smaller extent than do DZ co-twins, suggesting genetic
influence. As discussed in Methods, DF extremes analysis uses continuous data, and can estimate the genetic and environmental factors influencing the difference in mean intelligence between the two intelligence groups (high intelligence vs. the
rest of the population), by quantifying the differential regression to the mean for MZ and DZ co-twins of probands.

 

 

Fig 3 shows the general population properly distributed around the Standardised mean of 0.0. The fraternal twins of bright children (shown in blue) are at IQ 0.95 which is almost 1 sd above the mean. The identical twins of bright children (shown in light green) are at 1.47 which is almost one and a half sd above the mean. Bright children (actually young adults) have a mean of 1.98, almost precisely 2 sd above the mean, which is a shade higher than expected, if I have understood the inclusion criterion correctly and they were selecting IQ 124+ the top 5%.

As explained earlier, the authors find that the results strongly support the continuity hypothesis. Bright people are normal, and at the upper end of a normal distribution. 

We found no support for the genetic Discontinuity Hypothesis that nonadditive genetic variance is greater for high intelligence, as suggested by the emergenesis hypothesis (Lykken, 1982, 2006).

So, dear reader, even if you are bright, you are very probably normal.

In terms of future research strategy, the authors say: selecting individuals of high intelligence might increase power for gene-hunting based on the simple hypothesis that high-intelligence individuals are enriched for intelligence-enhancing alleles and harbour few intelligence-depleting alleles. In other words, intellectual development can be disrupted by any and many mutations, including non-inherited (de novo) mutations, but high intelligence requires that everything works correctly. This hypothesis provided the rationale for a genome-wide case-control association study for cases with extremely high intelligence (IQ >150) compared to unselected control individuals (Spain et al., in preparation). However, in an initial report, this design does not appear to have found richer results either for identifying individual DNA variants, or for genomic approaches such as comparing the total number of rare variants (which generally have negative effects and might be expected to occur less frequently in the high-intelligence sample). Nonetheless, it is early days for the use of high-intelligence samples to increase power for gene-hunting.

Sometime soon this team will tell us if anything has come out of the detailed genomic studies of high intelligence being carried out in Beijing. Follow this blog.