1. D OES SCHOOL MAKE YOU SMARTER ? Stuart Ritchie Tim Bates Differential Club 03/02/12

3. W HAT CAN WE DO TO RAISE IQ? Jensen (1969): Gloomy about reducing gaps… Ceci (1991): Review – school works. Herrnstein & Murray (1994) NLSY indicates minor effects: ~1 IQ point/year. Winship & Korenman (1997) NLSY reanalysis: ~2.5 pts/year Other studies similarly-sized: Cascio & Lewis, 2006; Falch & Massih, 2011; Hansen, Heckman, & Mullen, 2004 Renewed interest in trainability of g itself E.g. Improving fluid intelligence with training on working memory (e.g. Jaeggi, Buschkeuhl, Jonides, & Perrig, 2008) But see Moody, 2009; Shipstead, Redick, & Engle, 2010.

4. B RINCH & G ALLOWAY (2012), PNAS Norway – compulsory education reform - increases by 2 years But not in all municipalities Education reform leads to increase in average IQ of.6 points Measured by IQ test on entry to armed forces at age 19 Modeled using Instrumental Variables/2-Stage Least Squares analysis – this increase translates to an increase of 3.69 IQ points per year Similar to previous studies, but with a better design But what is being tested here? Arithmetic, word similarities, figures

5. IQ CHANGE WITH E DUCATION C HANGE

6. N ETTELBECK & W ILSON (2004), I NTELLIGENCE ‘The Flynn effect: Smarter not faster’ 2 samples of schoolchildren, separated by 20 years, both tested on vocab and inspection time As expected, Flynn effect occurs on VIQ (sig. increase)… …but not on IT (no sig. difference). So secular IQ gains – due to unknown causes – are not speed gains But what about IQ gains due to known causes (education)?

7. L OTHIAN B IRTH C OHORT 1921: LBC21 Scottish Mental Survey, 1932 IQ = Moray House Test (MHT) 87,498 tested Those in Edinburgh area followed up 1999-2001, 2003-2005, 2007-2008… Age 79 MHT; Asked about Education ( n = 550) At age 83 Reaction Time & Inspection Time ( n = 341) Jensen Box - RT IT stimulus

8. C ORRELATION MATRIX IQ11IQ79Edu Simple RT Simple RT SD 4-Choice RT 4-Choice RT SD IQ79.66*** Edu.44***.42*** Simple RT-.16**-.26***-.10 Simple RT SD-.16**-.29***-.09.71*** 4-Choice RT-.14*-.29***-.14*.53***.40*** 4-Choice RT SD-.13*-.28***-.08.32***.37***.60*** IT.18**.30***.11-.26***-.30***-.33*** Note: Edu = years of education; * = p <.05; ** = p <.01; *** = p <.001. Residualized variables, controlling for sex and age in days at time of testing/report

9. R ESULTS : EDUCATION DOES NOT IMPROVE S PEED Education predicts late-life IQ, controlling for early IQ lm(IQ79 ~ Education + IQ11 + Sex) F (1,479) = 10.65, p =.001 1 year education =.78 IQ points (95% CI =.31 - 1.25) Education effect on RT? lm(simpleRT ~ Education + IQ11 + Sex) F (1,286) =.03, p =.86 Effect of education on CRT? lm(choiceRT ~ Education + IQ11 + Sex) F (1,286) = 1.15, p =.28 Effect of education on IT? lm(IT ~ Education + IQ11 + Sex) No education effect, F (1,284) =.0004, p =.98

10. D ISCUSSION So does education make you smarter? Yes... in an IQ-score sense Q: Why the smaller IQ gains in our sample? Training vs. processing speed ‘transfer’ seems not to have occurred Limits “School” before age 11 may improve speed Or may not Replication in other samples?