There's no gene for 'humanness'. It's a lie told to children to make biology easier to learn.
> The genetic differences between Neanderthals and all modern humans (amounting to about 30,000) are far less than the differences between two random human beings alive today – around 3 million [1].
Clearly Neanderthals aren't more human compared to you than a randomly selected person.
1. https://www.theguardian.com/science/2023/jan/12/svante-paabo...