Is there gender inequalities between the same sex/ gender?

It's been clear that while talking about gender inequalities, we tend to pinpoint the differences between males and females. However, does gender inequalities occur between the same sex and/or gender group? If so, can you share some examples?
I'm thinking about this to decide whether or not I can write a paper on this topic. So please help me out! Thank you!

I can't lift more than 25 lbs. but my skinny a** twin brother can. Maybe it's my gender?

If there are inequalities between people of the same gender then how can it be the gender causing the inequalities?

I was actually discussing this issue with a friend whose younger brother is gay. We came to the conclusion that it has something to do with which partner is more dominant and which one is more submissive. We tend to assign the label masculine to more dominant qualities and more submissive qualities are referred to as feminine.

I've also heard it said that the word gender properly refers to language usage not sexuality. In other words, it is only words which have a gender, not people. Where's Boxerdc, he might be of some help here.

paradigm, the application of the word gender expanded during second wave feminism to the categories of people as well as words. this occurred because 2nd wave feminists pointed out that sex and gender are different variables in human interaction... someone's biological sex and gender identity might be different because they're two completely separate variables.

as for the main question, there IS discrimination within same sex communities. for example, men who express themselves by qualities socially "assigned" to any other gender identity are more likely to be discriminated against by "typical" males. this would mean a man whose gender expression is more feminine or more androgynous might be discriminated against because of his gender expression. i think this is a perfect topic for a paper!

--edit-- if you do write about this, keep in mind to point out the differences between sexual identity and gender identity