I was just reading this abstract for "Strategies and Methods for Research on Sex Differences in Brain and Behavior" and noticed one of my favorite annoyances:

A female’s reproductive status and ovarian cycle have to be taken into account when studying sex differences in health and disease susceptibility, in the pharmacological effects of drugs, and in the study of brain and behavior. To investigate sex differences in brain and behavior there is a logical series of questions that should be answered in a comprehensive investigation of any trait. First, it is important to determine that there is a sex difference in the trait in intact males and females, taking into consideration the reproductive cycle of the female.

Do you notice what I noticed?

It's probably old news, at this point, that researchers tend to see males as the normative, unmarked category in research, and therefore look at the variations that are brought in by females as confounding variables to be accounted for, but old news or not, it's still happening. This abstract is from Endocrinology in 2005.

There is no mention here of male hormonal variation. This is a good example of a situation where unconscious gender bias on the part of researchers may influence their findings at all stages, from the questions it occurs to them to ask to the ways they go about gathering data to answer them to how they analyze and discuss those data. When you see this in an abstract, it's a red flag to let you know to watch out for questions that aren't being asked, much less answered, and assumptions that are not being questioned.