Sex differences in brain organization

Paw preference in cats: distribution and sex differences

Paw preference assessed by a food-reaching test was studied in male and female cats. Of the total sample (N = 66), 34 (51.5%) were right-preferent, 24 (36.4%) left-preferent, and 8 (12.1%) ambilateral. In the total sample, there was evidence for an overall paw preference, general paw preference, right-, and left-paw preference. The distribution of the right- minus left-paw reaches was neither normal, nor U or J shaped. Of the males (N = 24), 10 (41.7%) were right-pawed, 12 (50.5%) left-pawed, and 2 (8.3%) ambilateral. In males, there was evidence for an overall, general, and right-, left-paw preference relative to no preference. The right- minus left-paw reaches fitted to guassian data with two prominent peaks due to the right- and left-preferents. In females (N = 42), 22 (52.4%) were right-preferent, 14 (33.3%) left-preferent, and 6 (14.3%) ambilateral. There was an overall, general, and right-preference but not a left-preference relative to no preference. The distribution of the right- minus left-paw reaches was neither normal nor U or J shaped. The female right-preferents showed a right-bias compared to males. The left-preferent males were more left-preferent than the right-preferent males are right preferent. The mean right- minus left- paw reaches for the female right-preferents were significantly higher than those for the male right-preferents. There was no significant difference between the right- minus left-paw reaches of the male and female left-preferents. The paw preferences exhibited consistency over time; no learning tendencies were established during testing periods for at least 10 days. Considering the mean right-paw reaches for each successive day (N = 10), the mean right-paw uses in the right-preferents was higher in females than males. The mean left-paw uses in left-preferents was about the same for males and females. In males, the mean left-paw uses for the left-pawed males were higher than the right-paw reaches for the male right-preferents. In females, there was no difference between the right paw reaches of the right-preferents and the left-paw reaches of the left-preferents. It was concluded that there is a right-bias in paw preference of cats, which is caused by the female right-preferents under the influence of a biological factor.(ABSTRACT TRUNCATED AT 400 WORDS)

Sex differences in brain organization: implications for human communication

This article reviews current knowledge in two major research domains: sex differences in neuropsychophysiology, and in human communication. An attempt was made to integrate knowledge from several areas of brain research with human communication and to clarify how such a cooperative effort may be beneficial to both fields of study. By combining findings from the area of brain research, a communication paradigm was developed which contends that brain-related sex differences may reside largely in the area of communication of emotion.