The Honorable Morris B. Hoffman will present The Effects of the Age and Gender on Third-Party Punishment. . . . Judge Hoffman will discuss studies showing there are significant interaction effects between the decision-maker’s age and gender, and the level of harm caused by the violation. For example, older men punish low-harm violations much less harshly than younger men, but this difference reverses when the harms become high — older men punish high harms more harshly than younger men. Women punishers did not exhibit this age-inversion phenomenon, but did punish more harshly than their same-age male counterparts across all harms.
One possibly explanation for the male-female discrepancy here is that it may be that a larger percentage of female judges were previously prosecutors than is the case for male judges, although I don't know that to be true. Another possibility is that female judges are more common in certain geographic areas where other factors lead to more severe punishments.