This article is sort of entertaining. It’s based on some kind of “study” which claims that women get the most catty and trash-talk the most when they are at the most fertile part of their monthly cycle.

…Females become far more critical of the looks of potential rivals when they are at their most fertile, say researchers.

This use of ‘indirect aggression’ to denigrate potential rivals is designed to boost their chances of finding a ‘good man’.

(Found through Enemies)