In The Gnome World I

Grey kept tabs on the meeting while traveling with the group. The Gnome world has an abundance of the darkness element which made it a haven for any Darkness Elementalist. Now they understood why all Gnomes had the darkness element, even though there are a few who have other elements along with it.

The darkness element was customary since the abundance of the darkness element would largely influence the elemental affinity of the children. There are people who specifically ensure their places have an abundance of the fire element or any other element. This will greatly increase the probability of having children with the same elemental affinity.