So I will be defending mayo as a gender. Okay. Mayonnaise is a gender. Why? Because there is no proof that it is not. According to the Solipsism theory (that most Psychologist will agree with) "there is nothing that we can prove besides our own conciseness". If that is the case, and you can't prove it is not, then external stimuli aren't valid as a scale to judge things by. Meaning that ideas (including gender) aren't anything further than my imagination. If I can imagine mayonnaise as a gender, there is nothing to prove me wrong.