It is funny how they try to obfuscate things with the XXY/XYY and intersex bullshit. These are pathological. Without medical science, the types of mutations that leave sex "ambiguous" would typically kill the infant, since they wouldn't be able to evacuate their urine and in worse cases, their solid waste. They need expensive and disfiguring surgery to correct their urethra so they can urinate properly.  Other mutations create even worse problems, like developmental disabilities and mental problems.  People with these mutations can't reproduce or also need surgery to be able to reproduce (if they are lucky).  The whole reason we classify sex is to describe the process of reproduction. You need a sperm and an egg to reproduce. There is no sexual spectrum when it comes to reproduction. You either have sperm or an egg. And sexual classification is nearly pointless without reproduction.