The previous chapter argued that several types of asymmetry, behavioural, perceptual and anatomical, are distributed in ways consistent with the RS analysis. But is it possible to be more precise, to predict associations between asymmetries? How are hand and eye preferences related, or asymmetries of handedness and cerebral anatomy? The aim of this chapter is to explain a recent discovery, that the joint distribution of certain asymmetries is predictable (Annett, 2000a). For some pairs of asymmetries the distributions are as expected for chance association, plus the influence of the right shift (RS +) gene on each variable independently. For other pairs the joint distributions are consistent with chance plus RS + gene, but with an additional association that I called a “pull to concordance”.