Testing Cheverud's conjecture for behavioral correlations and behavioral syndromes.

Recent research regarding correlations among behaviors--under the labels of behavioral syndromes and animal personalities--has typically assumed that phenotypic correlations between behaviors are representative of underling genetic correlations. However, for behaviors, the concordance between phenotypic and genetic correlations has not been rigorously examined. I tested this assumption using published estimates and found phenotypic and genetic correlations to be strongly related but found that the average absolute difference between the two was quite high and similar to that observed in other traits. Using absolute differences as the sole criterion, phenotypic correlations do not reliably estimate the magnitude of genetic correlations for behaviors, which is problematic for behavioral syndrome researchers. However, phenotypic correlations explained 75% of the variation in genetic correlations and their sign was typically the same as that of genetic correlations. This suggests that phenotypic correlations between behaviors reliably estimate the direction of underling genetic relationships and provide considerable information regarding the magnitude of genetic correlations. Thus, if researchers are careful about the questions they ask, phenotypic correlations between behaviors can be informative regarding underling genetic correlations and their evolutionary implications.