We quantitatively reviewed human sex differences in the magnitude and variability of durationjudgments, Data from 4,794 females and 4,688 males yielded 87 effect size estimates of magnitude and 28 of variability. The overall sex difference in duration judgment magnitude was small but statistically significant. It was moderated by whether study participants knew in advance (prospective paradigm) or only later (retrospective paradigm) that they would be required to judge duration. Although prospective judgments showed no overall sex effect, some levels of moderator variables showed a small but statistically significant effect. Retrospective judgments showed a larger subjective-to-objective duration ratio for females than for males, and several variables moderated this effect. Females' judgments also showed more intersubject variability than did males' judgments. Relative to males, females sustain attention to time more in the prospective paradigm and have better episodic memory in the retrospective paradigm.Since the publication of a landmark study on human sex differences in various abilities and behaviors (Maccoby & Jacklin, 1974), researchers have become increasingly interested in the topic. Researchers have conducted more than 100 meta-analyses on human sex differences. These differences range from nonexistent (effect size d not significantly different from 0) to small (d = 0.2 or less) to large (d = 0.8 or greater). For example, the sex difference on spatial perception tasks is small, but that on mental rotation tasks is large (Linn & Petersen, 1985).It is difficult to detect a general pattern in the evidence on sex differences involving memory and cognitive processes. Females perform relatively better on tasks involving production and comprehension of complex prose, fine motor skills, or perceptual speed, whereas males perform better on tasks involving visuospatial transformations, spatiotemporal operations, or fluid reasoning