As far as language distribution among the population of Iran is concerned, the metaphor of two homocentric circles can be conceived. People living in the inner circle speak in Persian and those who dwell in the outer circle, surrounding the whole body, speak in other languages.
About half of the population of Iran speaks in Persian and the other half in other languages. In this country, there are people speaking in languages which either are traced back to the family of Semitic languages, such as Arabic, Assyrian, or are related to the family of Mongol-Altai languages like Azari, Qashqai and Torkman Turkish, or are associated with the family of Indo-Iranian languages, such as Persian, Kurdish, and Balouch.
In addition to these major linguistic groups, there are minor groups about which a few investigations have been carried out, like Brahui language or different dialects of Turkish language such as Khalaji Turkish and gypsies’ language.
Furthermore, there are dozens of Persian and non-Persian dialects and accents in Iran, including Semnani, Mazandarani and Gilaki in Northern Iran, and Laki in Lorestan.
The Kurdish language in Iran incorporates major dialects such as Karmanji, Surani, and Behdini, and people from different parts of Kurdistan and Western Iran speak in these dialects. Some linguistics scholars consider the Gurani and Zaza dialects in Kermanshah, as well as Taleshi and Tati dialects in the area between Gilan and Azarbaijan as dialects which are traced back to the era of Medes’ who reigned over Iran 25 centuries ago.
Iran is considered a multi-ethnic country as stipulated in the Articles 15 and 19 of the Constitution. It goes without saying that different nationalities, such as Illamids, Sumerians, Akadians, and others lived in Iran from the immemorial times and the inscriptions inherited from the Achamenid, Arsacid and Sassanid eras are indicative of this fact.
These human groups are called ethnic groups or nations, for they have four common features, i.e. language, geography, history, and culture as well as common psychological specifications. In addition to Persians, five other nations live in Iran, i.e. Turks, Kurds, Arabs, Balouches, and Torkmans, who are treated as the Iranian citizens. Meanwhile, there are also other human groups who may lack one or more of the aforementioned features, such as Lors, Laks, Bakhtiaris, Taleshis, Gilaks and Mazandaranis. Unlike the mentioned nations, these groups speak no other distinct language than Persian and they, in fact, are speakers of dialects or accents of Persian, Kurdi, and Turkish languages. Although some of the linguists conceive of dialects like Laki, Taleshi, or Gilaki as semi-languages due to their semantic and syntactic features, what differentiates these human groups from others is their particular culture rather than their dialects or accents. In order to make them distinguished from the first group, I prefer to call them “ethnic groups”. Furthermore, in addition to Muslims who make the majority of the population, religious minorities, such as Mandaeans, Jews, Zoroastrians, Assyrians, Chaldeans, and Armenians (the last three ones are Christians), live in Iran, too. Some of these religious minorities, like Armenians, are ethnical minorities as well. Mandaeans are originated from Arabs of Khuzestan (a southwestern Iranian province) and are followers of John. The major religious minority in Iran are Sunni Muslims who are scattered among different Iranian ethnicities like Persians, Kurds, Torkmans, and Balouches.
Here it is necessary to mention the densely populated areas where different Iranian ethnic groups mostly reside in. Mentioning these major concentration areas, however, does not necessarily mean that these ethnic groups do not live in other regions and provinces of the country. As far as geography is concerned, the densely populated areas for each nation could be described as follows:
Persians live in the central and eastern provinces; Azaris reside in eastern and western Azarbaijan as well as in Ardebil, Zanjan, Golestan, and Khorasan; Qashqais dwell in the Fars province; Kurds dwell in Kurdestan and western Azarbaijan provinces as well as Kermanshah and Ilam; Arabs are in Khuzestan, Ilam, southern islands and ports, Baloches in Sistan & Balouchestan province, and finally Torkmans are concentrated in the Golestan province.
Meanwhile, there are few official figures regarding the population of the Iranian ethnic groups but the estimates presented by the Iranian and foreign researchers suggest a break down as follows:
Azari Turks ----------------- 33-35%
Total ----------------------- 53-55%
Others, including Persians and those who speaking dialects and accents like Lori, Bakhtiari, Lak, Gilaki, Taleshi, Mazani, etc. account for 45 % to 47% of the population. Meanwhile, the Sunni Muslims in Iran are thought to make up some 10-15%.
The whole diversity of the ethnic groups, religions, and languages fit into the Iranian nation-state structure and it is axiomatic that both religion (Islam) and nationality (Iranian) are the two major factors contributing to the creation of spiritual unity among all Iranian ethnic and religious groups.