Relation of brain weight to body weight in cats to sex and paw preferences: anomalous results in left-preferent cats.

The well known relationship between brain weight and body weight was restudied in cats considering paw preference assessed by the food reaching test. The brain weight was found to be directly related to the body weight in the total sample, males, females, right-preferents, ambidexters, male right-preferents, male left-preferents, and female right-preferents. There was, however, no significant correlation between these parameters in the left-preferent cats. As a further anomalous result, there was a negative linear correlation between brain and body weights in the left-preferent female cats. It was suggested that the well-known allometric law that brain size increases with body weight should be reanalyzed in studies of neural evolution considering cerebral lateralization and sex-related differences.