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JL

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Correct Models Not Required
A reviewer has asked for evidence that a MGCFA using a higher-order model would find the same patterns of biased and unbiased parameters that a correlated group factor model would.
The Power to Compare Qst and Fst
Tests of whether Qst is above or below Fst lack power in many realistic scenarios involving few populations.
Wilks' Theorem About Composite Scores
In 1938, Wilks posited that the correlation of a set of linear composites approaches one when the component variables are positively correlated and the weights are also positive. Simulations confirm this theorem holds up.
The AC'RE Model: An Application to Mathematics Performance
The AC'RE model applied to standardized PIAT Mathematics scores.
MGCFA of the Programme for the International Assessment of Adult Competencies Tests in the United States
The tests of the PIAAC are largely unbiased, with one exception.
The AC'RE Model
The AC'RE model can be used to obtain the same estimand as a study of twins reared apart using cousins. Here's an application and extension of that model with height in the NLSY-79 Child and Young Adult data.
Growth Mindset Interventions and Measurement Invariance
An intervention changed the heritability of growth mindset. This also led to measurement non-invariance, as expected if measurement invariance means tests measure the same things in different groups.
Gaps in LSAT Performance in Canada
Applying the Method of Thresholds to Canadian LSAT performance data.
The Flynn Effect in Spain, 1991-2022
A recent study of the Flynn effect provided data to assess whether the gains were on g and the extent of bias. Bias led to generally underestimated gains, but the gains were subtest-specific and not on g.
Pilot Studies Are Often Unwise
Simulations are offered to show that power analyses should not follow from small pilot studies and that meta-analyses with publication bias won't reliably capture true effects.
Probability of Superiority Curves: A Better BESD
Supplies two functions for working with Jané's POSC package. One extends posc_comp() to arbitrary numbers of plots and the other provides a way to make a dataframe for ggplot2 from a POSC object.
Birth Order Effects on Status
Code to check the significance of birth order effects on modern social status in Gregory Clark's data coupled with an assessment of gender interactions.
Equilibrium Heritability
Assortative mating changes heritability, but various forces causes this to asymptote over time. This means twin-based heritability estimates are incompatible with the work of Gregory Clark. There is no current resolution.
Intelligence Can Be Measured via Neural Processing Speed
Using event-related potentials, the measurement of intelligence is possible (i.e., r ERP-g/IQ-g ≈ 1). Since influencing neural processing speed without affecting intelligence is possible, it is highly unlikely that formative models are appropriate for intelligence.
Polish School Reform Effects on Intelligence
Reanalyzing data on a Polish schooling reform that made primary school more intensive to see if it accelerated the rate of g development.
Dyscalculia Measurement in Hungary
Code supplement for a paper on the Hungarian Diszkalkulia Pedagogiai Vizsgalata or DPV tool.
The Law School Admissions Test, Race, and Threshold Selection
Plotting data from the LSAT by race and sex for the years 2006-2018. Includes MCAT data from 2022-2023.
Personal ggplot2 Theme
Similar to base R
Height Polygenic Scores Work in Premodern Human Populations
New data adds to the case for the robustness of height polygenic scores over a very long period of time.
An Example of Unusable German Student Lockdown Data
Breit et al. (2023) produced some interesting results, but their data can't be modeled with anywhere near acceptable fit so it's unusable.
Matrix Rules and Measurement Invariance
Teaching matrix rules invalidates comparisons with those who aren't taught them when it comes to figural matrices.
Should students learn the real rate approximation?
In Western economies, it's probably not an issue, but it becomes problematic when talking looking at Latin America and Africa.
Happiness and Wellbeing vs. Income
Killingsworth (2021) used an oddly scaled axis for income that made it seem like he discovered a linear relationship between income and wellbeing. He did not.
Electricity and Income
The relationship has been misrepresented by logging a single axis. The relationship is still substantial.
2021 Replication of High Intermittent Generation System LCOE
The levelized cost of energy is falling for intermittent generation renewables (wind, solar), but it imposes high system costs because it necessitates a second dispatchable system that must run inefficiently.
Publication Bias in the Literature on Mental Health and Childhood Maltreatment
Reanalysis of Baldwin et al., since they did not use a proper publication bias correction method. Here, I used trim-and-fill.
Necessary vote capture to win a race
Simple function to calculate the proportion of votes that need to be obtained to change the result of a race.
The Effect of Education on Political Identification in the ANES
Does education affect politics? Does politics affect education? Apparently only the former is true.
Anti-Discrimination Laws, Mental Health Days, and Interaction Testing
Gelman & Stern (2006) is a must-read.
State-level Admixture and Test Scores in the United States
Assessing a possible explanation for variance in group differences across states in the USA
Ancestry and Self-Identification
Quasibinomial model of the data on genetic ancestry and self-identified race from Bryc et al. (2015)
The 2022 National ACT Profile Report
Group differences in ACT performance in the year 2022 are examined.
The Method of Multiple Thresholds
Applying a method for determining mean differences and variance ratios to newly-released SAT and PSAT score data from Michigan
Diversity Indices, Ideology on Campus, and College Rankings
Ideological diversity may be negatively related to how highly colleges and universities are rated.
New Workers are Unlikely to Harm Wages
A simple demonstration with the Cobb-Douglas model.
Quick Heteroskedasticity-Robust Regressions in R
A simple function to wrap lm() for HC-robust standard errors 1-5.
An Underpowered Analysis of the Relationship between Brain Size and Climate
Will et al. (2021) was severely underpowered. Negative conclusions based on its data are not justifiable.
Spearman's Hypothesis in Old Data
Nichols (1970) provided a large dataset that could be used for testing Spearman's hypothesis, so I tested it.
Reanalysis of Romanian Foster Care Data
Humphreys et al. (2022) made strong conclusions with low-quality data and weak results.
Are Emissions and Manufacturing Decoupled?
Using data from FRED, the answer is yes.
Bounding the Transitivity of Correlations
A formula is presented to compute the expected bounds of the correlation r_{xz} given knowledge about correlations r_{xy} and r_{yz}.
Bearman & Brueckner (2002) did not rule out twin hormonal transfer
In a study of dizygotic, opposite-sex twins, it was argued that hormonal explanations for male twins' elevated rates of homosexuality were ruled out. They were probably not.
Dimensionality and Graph Analysis of Hanania's Survey
Richard Hanania recently gave out a survey to his blog readers. Here is some information on the data's dimensionality and an interactive TMFG plot of it.
Replotting the College Board's Famous 2011 SAT Results Barplot
The barplot format was not amenable to quick visual inspection, so I turned it into a line chart.
Replotting Yuan et al.'s (2022) Cooperation Plot
Regraphing a plot with confidence intervals rather than a prediction interval, since the latter was widely misinterpreted.
The Reason Ecological Correlations are Inflated
Clustering tends to reduce within-unit correlations, making unit means unreliable proxies of the correlation in the population since they are stratified more strongly than individuals are.
Reanalyzing RAND's Meta-Analysis of Right to Carry Law Effects on Violent Crime Rates
RAND perform a review of the evidence on the violent crime promoting effects of concealed carry but did not assess publication bias, so I did.
Thresholds, True Scores, Group Differences
A brief note on how selection thresholds do not eliminate group differences.
Odds Something Happens At Least Once
Simple functions for simple purposes: finding out the probability of an event happening at least once, given a known probability and number of tries, and finding the number of tries given a desired probability and a known probability per try.
A Comparison of Abortion Law in Europe and America
European countries are generally more restrictive about abortion than American states, at least in terms of how many weeks of pregnancy women are allowed to get abortions in.
Overrepresentation Plot
When comparing groups, absolute comparisons may need to go to the extremes.
Mean Absolute Deviations, Standard Deviations, Heritabilities, and Environmentalities
Answering the question of how different people are given some level of relatedness, heritability, shared environmentality, and rGE.
2016 Firearm Ownership and Homicide Rates by U.S. State
Relationship between firearm ownership and homicide rates in each U.S. state, circa 2016.
Does Practice Reduce General Intelligence-Related Variance?
Practice on a discrimination reaction time task did not seem to reduce the general intelligence related variance in Fleishman & Hempel's study.
The Correlation-Adjusted Bonferroni Correction Method
Shi, Pavey & Carter (2012) provided a method for computing the Bonferroni method for controlling the FWER when outcomes are correlated, allowing for strong FWER control with greater power.
The Domain Specificity of Working Memory is Unknown
Kovacs, Molenaar & Conway (2019) made claims in favor of process overlap theory based on analyses that required more analytic leverage than their data could afford and failing to properly test for interactions.
The Relationship Between Test Effort and IQ Might be Causal
Reanalysis of Bates & Gignac's (2022) study of incentive effects on IQ suggests that they interpreted the wrong quantity and were underpowered to detect their desired effect. Evidence is consistent with a causal relationship, but it remains to be tested.
Measurement in Bates & Gignac (2022)
Measurement invariance analyses for Bates & Gignac (2022). These are almost indeterminate due to the choice to use different forms for retesting and, presumably, a small intervention effect.
What Happens if you Copy Nancy Pelosi?
Copying and holding Nancy Pelosi's declared trades nets huge gains.
Classical Reliability Correction for Cohen's d and the Point-Biserial
Functions to correct Cohen's d for reliability and to convert it to the point-biserial and back.
A Better Version of RMSEA for Nested Model Comparisons
Taking the difference between model RMSEAs is an imprecise and insensitive method of using RMSEA. Here is a function for computing an improved version suggested by Savalei, Brace & Fouladi (2021).
Assessing the Meaning of Measurement Invariance
Protzko (2022) claims to show that measurement invariance does not yield evidence that tests measure the same constructs in different groups. That conclusion was based on a failure to test that hypothesis and it was bolstered by the use of insensitive fit indices. Done properly, the opposite conclusion is supported.
Education and Intelligence - The Vietnam Experience Study
Education does not affect intelligence, but instead, specific test scores or skills. The effect of education on SES is not mediated by cognitive gains or even subtest score gains. Intelligence is extremely stable over a nearly twenty-year period.
German Schizophrenia Eugenics
A recollection of Gwern's comments on the alleged failure of Nazi Germany's eugenics program to affect schizophrenia rates.
Assortative Mating and the Polygenic Prediction of IQ
Includes a meta-analysis of assortative mating with respect to IQ and a brief investigation of the degree to which within-family PGS validity attenuation might be attributed to that phenomenon.
t Tests and ANOVAs with Summary Statistics
Functions for summary statistic t Tests and ANOVAs
Power and Effect Size Exaggeration
Produces Yarkoni's (2009) plots and provides a function to determine the mean significant r at some sample size.
Power, Effects, and Robustness of Pesta et al. (2020)
Power analysis for all groups in Pesta et al. (2020) and simple partial robustness checks.
Are Rapid Antigen Tests a Coin Flip?
No, that perception is based on a misunderstanding of Bayes' rule.
Was the Greater Male Variability Hypothesis Debunked?
No. The analysis that claim was based on did not allow that conclusion.
Minimum Detectable Difference in Pearson's r Between Subgroups in a Meta-Analysis
A function to wrap subgroup_power() to determine minimum detectable effects.
Check your Checksums
For reproducibility, provide checksums for your data and data subsets and modifications.
Differences in the Relationships between Empowerment and Satisfaction in Minority and Majority Faculty
Measurement models for empowerment and satisfaction were tested in minority and non-minority faculty. Differences were observed.
Reanalysis of Pesta et al. (2020)
A reanalysis of the heritability meta-analysis by Pesta et al. (2020).
dMACS_True
Function for a combination of dMACS and dMACS_Signed, for proper magnitudes and directions of effects.
Testing Explanations for the Gender Equality Paradox
An assessment of the degree of bias with respect to means by sex in cross-national personality assessment, using Johnson's IPIP-NEO 120.
Neuroticism and Gender Equality
An evaluation of the gender equality paradox for neuroticism alone, to serve as a data source for a comment on Benenson, Webb & Wrangham (2022).
dMACS_Signed
I wanted a function for the signed version of dMACS, a formula to quantify the effect of bias in the loadings and intercepts of SEMs on the means of indicator variables.
Felig et al.'s Results are Explained by Filtering
An assumption-laden decision to filter based on variability explains the marginally significant interactions in Felig et al.'s paper. The results do not replicate with perceived actual temperature as DV.
Verbal IQ is Related to Tolerance in the GSS
An assessment of the relationship between verbal IQ and tolerance in the General Social Survey.
A Method for Accounting for Change in Ordinal Variables
Ferreira, Almeida & Luiz (2013) provided a method for assessing change in ordinal variables. However, they did not provide code to actually use their method. Here is some code.
A Trendbreak in Homicide Rates in 2020?
Checking whether an RDD for May 2020 is significant, plotting with that as a breakpoint.
Between-Group Heritability in a Recent Global Admixture Study
Connor & Pesta recently provided additional data on this topic.
Venn Diagram Simulations
Illustrations of how the association between variables affect Venn diagrams.
Sex Differences in Variance Ratios on Cognitive Tests
Assesses subtest variance ratio differences by sex, with an attempt to remove confounding by the relationship between differences and variance ratios.
Canivez et al. (2009) - Reanalysis
The WASI and the WRIT measure the same g factor.
Kaufman et al. (2011) - Reanalysis
Kaufman et al. correlated PAF-based g factors, so I redid their analysis with CFA.
Just One g - Updated Meta-Analytic Results
Contains results for my analysis of the correspondence between the general factors from various cognitive test batteries.
How Many g Factors?
I conducted several joint confirmatory factor analyses to assess whether different tests assessed the same g.
Marks (2010) Reanalysis for Lasker, Nyborg & Kirkegaard (2021)
Supplementary material for a paper on Spearman's hypothesis.
Buczyłowska, Petermann & Daseking (2020) - Just One g?
Buczyłowska, Petermann & Daseking gave the WAIS-IV and an executive function battery to a sample of German adults. They measured the same g.
Reanalysis of Wong et al. (1995)
Wong et al. analyzed the relationship between "academic" and "social" intelligence. It appears they could not meaningfully distinguish them.
Piagetian and Psychometric Intelligence
Found some additional datasets for assessing this question with JCFAs and other atypical tests.
Are there sex differences in sex ratio relationships with wellbeing?
Checking something from Thomas Richardson's (2021) new study.
Odenstad et al. (2008)
Graphs for their results and a note about Korean adoption.
Quiroga et al. (2019)
Reanalyzed Quiroga et al. (2019) with their implied higher-order model
Test Preparation?
It is commonly claimed that group differences in standardized test performance are explained by differences in the use of test preparation services.
Additional FAs for a Friend
More factor analyses for a friend of mine.
Factor Analysis for a Friend
A friend needed some help factor analyzing something because he was used to STATA.
Just One g
Just the meta-analytic result from an earlier analysis.
The Modified Achievement Goal Questionnaire - MGCFA Extension
Campbell et al. (2008) tested invariance of the AGQ-M but forgot to go all the way. Here's an extended analysis.
Spearman's Hypothesis Properly
Reupload of something previously up here.
Latent Socioeconomic Status?
Latent variables are used to reduce measurement error in socioeconomic status measures. This has not been justified.
Binomial Effect Size Display
Functions for working with one of Rosenthal & Rubin's methods.
Dataframe from Many .csvs
A friend needed some code.
Dunning-Kruger Effect
There's not very good evidence for this effect. I replicated Gignac's recent study on it.
NFL Wonderlic Scores
In light of ongoing controversy regarding the cognitive effects of concussions among NFL players, I decided to chart their scores.
HEXACO - Saudi Arabian Sample
A colleague asked for a CFA.
From Heritability to Probability
R functions for Omri Tal's (2009, 2012) equations.
Northeast Asian Adult IQ Estimates
Addresses a gap in the visible literature.
Cooper & Zubek Power Analysis
Post-hoc power analysis of Cooper & Zubek (1958).
The BAFACALO Battery
I analyzed whether the Brazilian BAFACALO battery and its associated dataset provided evidence for several common findings from western samples.
The Study of Latin American Intelligence (SLATINT)
A cross-national effort to assess cognitive development in seven countries produced interesting and potentially useful results. I evaluated whether the countries in the sample could be compared.
Testing Factor Models with Behavior Genetics
I provided code to test common and independent pathway models with sibling data.
Dimensional Assessment of Cognitive Batteries
Decker et al. (2020) produced an incoherent case against current best practices in dimensionality assessment.
The Partialing Fallacy
Gordon (1968) introduced the so-called partialing fallacy. This short post shows it is still worth worrying about.
Armspan and Winning Fights?
Richardson (2020) claimed some support for sexual selection for arm length based on the relationship between armspan and UFC fight win percentages but his sample was selected.
Are Executive Function and Intelligence Separate?
Freis et al. (2020) put up a pretty strange preprint so I thought I would reanalyze it.
IQ and Motivation via Duckworth et al. (2011)
The meta-analysis by Duckworth et al. (2011) should be less than convincing to measurement-concerned researchers.
The Effect of Education on Cognitive Ability in the Vietnam Experience Study
Replicates Ritchie, Bates & Deary (2015) and extends their analyses.
The Equal Environments Assumption
Prelude to a more comprehensive meta-analysis of twin model assumptions and their effects on estimates.
Observed Differences Do Not Necessarily Reflect Latent Ones
It is shown that the WISC-R and K-ABC model the same general factor and, despite different observed score gaps, differences in g are similarly-sized.
Almost-sure p-values
I've provided a function for using Naaman's "almost-sure" p-values.
Millsap's Approach to Residual Invariance Failure
Millsap proposed quantifying the proportion of the variance in observed variances which differed between groups due to differences in residual variances. I applied that to five recent parameter estimates.
Comprehensively Assessing the Jensen Effect
Despite discussion, there has not been a comprehensive meta-analysis of the Jensen effect. I aimed to remedy that.
The Reynolds Intellectual Assessment Scales are Unbiased with Respect to Migrant Background
Gygi, Fux & Grob found bias in a model with g; reanalysis disconfirms that.
Ability and Prior Job Knowledge in Complex Training Performance
Reanalysis of the matrix and path model from an old study.
Estimating Between-Group Heritability
There are few published empirical estimates, so I derived some with three different methods.
A cross-cultural comparison between South African and British students on the Wechsler Adult Intelligence Scales Third Edition (WAIS-III)
Assessed interpretive errors and inconsistencies in a study by Cockroft et al. (2015).
Morbid Curiosity
Reanalysis of Scrivner's (2020) scale validation CFA data.