What human traits are highly variable

The most variable traits are situated within the triangle of the eyes, mouth and nose.

(credits to the owner of this answer :)

eye colour.

hair colour.

skin colour.

lobed or lobeless ears.

ability to roll your tongue.

Hope this helps

answer; the correct answer is conflict- related aggression; +

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.