From Intellectual Takeout, by Martin Cothran
The gist of the article is that if gender is a social construct, so is race.
The article is pretty short, so it won't take much of your time.
April 24, Addendum. In case anyone reads this
The author posited an interesting theory about racial and sexual identity, but turned out to be wrong about both.
In the case of racial identity, the evidence we have indicates that Rachel Dolezal is not a White woman who thinks she was born into the wrong race but someone who appears to have simply changed her appearance and identity for career reasons. That, as Ron Powell points out in the thread, makes the comparison intrinsically invalid.
In the case of sexual identity, gender turns out not to be a social construct but a physical characteristic that shows up in brain scans. Thanks to Safe Bet's Amy and Anna Harrington for providing that information, to Amy in particular for providing a link to multiple studies on the subject.
I am leaving the post up not because it has any validity but because the thread contains good counter arguments in case you ever have use of them.