What is a "Normal" Human?

Under the JK Rowling tweet about "erasing the concept of sex", I found an interesting article: You Can't Be a Feminist Without Acknowledging Biological Sex.

It brings up an interesting point:

The existence of people born with Syndactyly, for example, does not mean that humans don’t normally have 10 fingers and 10 toes.

I think this is at the heart of the debate. What is "normal" and what is not.

There is a wonderful TED talk by Aimee Mullins titled "The opportunity of adversity" (coincidentally, I had blogged about it 10 years and 2 days ago)

In it she brings a view of "disability" that should make anyone question the concept of normal.

Humans tend to call as "normal" what is "common". If 99% of people look and act in one way that is what most people call "normal". But "normal" has a connotation that is completely different from "common". The opposite of "normal" becomes "abnormal" - something to be corrected, something that shouldn't have been. And that's why the word "normal" creates all kinds of problems.

This has disastrous consequences. People with mental health issues are stigmatized against taking help because they get labelled "abnormal" by people who lack experience in understanding the spectrum of human existence. What is uncommon isn't abnormal. It is just uncommon.

Let's come back to the case of fingers. Do humans "normally" have 10 fingers or "commonly" have 10 fingers? What makes 10 fingers normal? Since we are using scientific terms like "syndactyly", let us also take a step back and look at the science of evolution. The way life evolves is through random genetic changes. All the diversity on earth (including human species) is the result of millions and billions of "mistakes" during cell division. Is there, then, anything abnormal about having a genetic makeup that causes a visible change in appearance from one's parents? Aren't there a lot of genetic differences between every individual on the planet (many of which perhaps don't cause visually apparent differences)? What is the rationale behind arbitrarily calling some set of human characters as "normal"? "Common", sure! But "normal"?

Let us take a human being born with 10 fingers. What if they lose a finger in an accident? Do they become abnormal? Sure they have lost a finger and probably a lot of functionality associated with that finger. You could call them "disabled". But watch the Aimee Mullins talk above again. Calling them "abnormal" creates unintended alienation. See how labeling people is a very hard thing?

That is the context in which saying biological sex can have only two normal values - "male" and "female" - creates problems.