ABSTRACT
The summary of findings to be presented shows that there are a substantial number of anatomical and physiological traits with ten or more findings that appear to exhibit culturally universal sex differences. The two main categories of hormones that have been studied with respect to possible sex differences are sex hormones and stress hormones. This gradual reduction in neurons mainly involves cells comprising gray matter rather than white matter, to be discussed later in the chapter on the brain. The chapter provides a condensed summary of findings regarding sex differences for traits that have at least ten relevant studies. The feeling covered include negative emotions such as anger, disgust, fear, jealousy, sadness, anxiety, and stress to positive emotions such as humor appreciation and empathy. Studies of sex differences in emotional expressions are also reviewed.
