Effects of menstrual cycle phase on aggression measured in the laboratory

This study investigated the effects of menstrual cycle phase on aggression in two groups of women, which differed in the severity of their self-reported perimenstrual symptoms. A low- and a high-symptom group were recruited using the Menstrual Distress Questionnaire (MDQ) to define the groups. Twenty-two subjects (11 low and 11 high symptom) participated across one menstrual cycle: during the premenstrual, menstrual, midfollicular, and ovulatory phases. The Point Subtraction Aggression Paradigm was used to assess aggression on each day of participation. There were three main findings; a) rates of aggressive responding did not vary across phases of the menstrual cycle; b) the high-symptom group emitted higher rates of aggressive responding across the menstrual cycle than did the low-symptom group; and c) rates of aggressive responding correlated with the MDQ's behavioral and psychological scales and not the somatic scales. These findings indicate that the menstrual cycle phase does not differentially affect this laboratory measure of aggression. The differences found between the two symptom groups parallel a few reports indicating that women who differ in retrospectively reported mood and behavioral changes related to their menstrual cycle also differ on a number of other psychometric measures. Aggr. Behav. 24:9–26, 1998. © 1998 Wiley-Liss, Inc.