Abstract Assessment of 270 individual databases produced by 135 human operators in five local and four remote human/machine anomalies experiments conducted in the PEAR laboratory between 1979 and 1993 reveals several significant gender-related differences in performance. Although the 140 databases produced by 62 females are much larger on average than 130 produced by 73 males, the male average results display significantly stronger correlations with the operators’ pre-recorded intentions to shift the output distribution means of a variety of random devices to higher or lower values. Both groups demonstrate greater success in the high-intention efforts than in the low, but whereas a majority of the males succeed in both directions of effort, producing intentional results that are relatively symmetrical in comparison with their empirical baselines, most of the females’ low-intention results are opposite to intention. The baseline data generated by the males largely concur with calibration and theoretical expectations, while the females tend to higher than chance values. The female data also frequently display larger score distribution variances. These disparities are more pronounced in five local experiments than in four remote databases. No gender differences appear in two experiments that yield null overall results, suggesting that the gender-related patterns observed in the successful experiments may be indicative characteristics of the primary human/machine anomalies.