Iran-Arya

Just as northern India has paler skinned and eyed people so too does Iran retain its Indo-European genetic background despite the muslim-arab and mongol invasions. Though much of it has become diluted, though it comes out more in some persians. Babylonian boundary erosion impacts tolerant empires more so than insular tribes. The Aryans who came to northern India were lenient at first, but after pollution of their genes and values, they became stricter in outlook by solidifying and reinforcing the caste system. An Aryan has many meanings which include: being a member of the Indo-European ethnolinguistic family, a sense of duty, purity and clarity of thought and deed, loyal and genuine, courageous, dilligent, self-relaint, persevering, hospitable within limits/dont overstay your welcome, strong and alert/intuitive.

The blonde and redhead Tocharians were related to the Scythians and ancient Persians along with other IndoEuropean tribes.

Indo-European languages
https://en.wikipedia.org/wiki/Indo-European_languages

Aryans and Iran
http://www.iranchamber.com/people/articles/aryan_people_origins.php