Distribution of Paw Preference in Female and Male Rats: Assessed by A Modified Version Food-Reaching Test

Summary We re-studied the distribution of paw preference in male and female rats using a new food-reaching test. Paw preference was assessed using a modified new version of food reaching task in quadrupedal position. Of the total sample (N=165). Of 165 rats, 86 (52.12%) were right-handed, 72 (43.64%) were left-handed, and 7 (4.24%) were mixed-handed. Of the in male (N=74) 36 (48.65%) were right-handed, 35 (47.30%) were left-handed, and 3 (4.05%) were mixed-handed. The right-minus left paw reaches fitted to gaussian data with two prominent peaks due to right–and left preference. In female (N=91) 50 (54.94%) were right-handed, 37 (40.66%) were left-handed, and 4 (4.40%) were mixed-handed. The female right-preference showed a right-bais compared to males. The males leftpreference were more than female left-preference.The distribution of right minus left paw reach was not U-shaped, it was J-shaped like in humans. The results indicate that the distribution of paw preference in rats is similar to that of other animals and to human handedness. It was concluded that there is a right-bias in paw rats, which is caused by the female right-preference under the influence of a biological factor. The right-pawed males were found to be least lateralized than the male left-preference, and female right-and left preference. The brain is in general more lateralized than the female brain.