The multi-variate phenotypes measured in this study were obtained from multiple test batteries that were performed in multiple laboratories. Previous studies have raised the issue of robustness and stability of behavioral traits. Wahlsten et al. (2006) addressed this issue by comparing phenotypic data across laboratories and previously published studies for behavioral measures of locomotor activity and ethanol preference. We compared data collected for the same measure across our phenotyping laboratories and also with previously reported data for traits that were measured across multiple laboratories in the present study.
