Even people who otherwise support transgender equality often draw the line at transgender women competing against cisgender women. We have a couple of new opinions expressed lately. What makes these more unusual than most is that they are grounded in science.

Steven Petrow investigates at Washington Post.

This charged debate is timely because of a landmark rule change instituted by the International Olympic Committee (IOC) this year. In Rio, transgender men (female-to-male athletes) will be allowed to compete without any restrictions (based on the sexist assumption, I suppose, that trans men could never dominate their sports). Trans women, meanwhile, are no longer required to undergo gender-reassignment surgery to compete in female divisions, and the previously mandated two-year wait after transitioning has been jettisoned.