## Did Turkheimer et al (2003) replicate?

Lots of published psychology studies don't replicate well, in particular cute things like interactions, counter-intuitive or priming effects. In general, traditional behavioral genetics studies have replicated well. This is not…

## Embryo selection and genetic correlated traits: A reanalysis

There seem to be ways to post knitr documents to Wordpress blogs, but until that's set up, I will be publishing them over at RPubs and posting a link here.…

## Error in the previous version of FA_residuals()

In the spirit of reproducible science, this is a post about an error I fixed in a function that affects all prior analyses with that. When factor analyzing data, the…

## R functions for analyzing missing data

I'm reading Missing Data: A Gentle Introduction and it mentions various methods to understand how data are missing in a given dataset. The book, however, is light on actual tools.…

## Estimation of piecewise linear functions

Suppose you have some dataset where you know or suspect that the real generating function is actually a piecewise function with k pieces each of which is a standard linear…

## A more intuitive explanation of the correlation

Someone asks on Reddit: Can someone intuitively explain the correlation formula? I know what the Cov(X,Y) means. It tells you if the relationship between the variables X and Y is…

## Correcting for n-level discretization?

When one has a continuous variable and then cuts it into bins (discretization) and correlates it with some other variable, the observed correlation is biased downwards to some extent. The…

## Causality, transitivity and correlation

Disclaimer: Some not too structured thoughts. It's commonly said that correlation does not imply causation. That is true (see Gwern's analysis), but does causation imply correlation? Specifically, if "→" means…

## Stereotypes are relevant for judgments about individuals even when one has individualized information

Title says it all. Apparently, some think this is not the case, but it is a straightforward application of Bayes' theorem. When I first learned of Bayes' theorem years ago,…