Sex Differences in Episodic Memory Variance

Episodic memory is a neurocognitive (brain/mind) system, uniquely different from other memory systems, that enables human beings to remember past experiences. The notion of episodic memory was first proposed some 30 years ago. At that time it was defined in terms of materials and tasks. It was subsequently refined and elaborated in terms of ideas such as self, subjective time, and autonoetic consciousness. This chapter provides a brief history of the concept of episodic memory, describes how it has changed (indeed greatly changed) since its inception, considers criticisms of it, and then discusses supporting evidence provided by (a) neuropsychological studies of patterns of memory impairment caused by brain damage, and (b) functional neuroimaging studies of patterns of brain activity of normal subjects engaged in various memory tasks. I also suggest that episodic memory is a true, even if as yet generally unappreciated, marvel of nature.

In recent years, the magnitude, consistency, and stability across time of cognitive sex differences have been questioned. The present study examined these issues in the context of spatial abilities. A meta-analysis of 286 effect sizes from a variety of spatial ability measures was conducted. Effect sizes were partitioned by the specific test used and by a number of variables related to the experimental procedure in order to achieve homogeneity. Results showed that sex differences are significant in several tests but that some intertest differences exist. Partial support was found for the notion that the magnitude of sex differences has decreased in recent years. Finally, it was found that the age of emergence of sex differences depends on the test used. Results are discussed with regard to their implications for the study of sex differences in spatial abilities.

In 1993 Oliver and Hyde conducted a meta-analysis on gender differences in sexuality. The current study updated that analysis with current research and methods. Evolutionary psychology, cognitive social learning theory, social structural theory, and the gender similarities hypothesis provided predictions about gender differences in sexuality. We analyzed gender differences in 30 reported sexual behaviors and attitudes for 834 individual samples uncovered in literature searches and 7 large national data sets. In support of evolutionary psychology, results from both the individual studies and the large data sets indicated that men reported slightly more sexual experience and more permissive attitudes than women for most of the variables. However, as predicted by the gender similarities hypothesis, most gender differences in sexual attitudes and behaviors were small. Exceptions were masturbation incidence, pornography use, casual sex, and attitudes toward casual sex, which all yielded medium effect sizes in which male participants reported more sexual behavior or permissive attitudes than female participants. Most effect sizes reported in the current study were comparable to those reported in Oliver and Hyde's study. In support of cognitive social learning theory, year of publication moderated the magnitude of effect sizes, with gender differences for some aspects of sexuality increasing over time and others decreasing. As predicted by social structural theory, nations and ethnic groups with greater gender equity had smaller gender differences for some reported sexual behaviors than nations and ethnic groups with less gender equity. Gender differences decreased with age of the sample for some sexual behaviors and attitudes.