Genetics: Genetics confirm that the Scythians belonged to the Old-European R1a and N1a Haplogroups. They were tall, they had mostly blonde hair and green or blue eyes exactly as Ammianus Marcellinus described them. The best genetic proofs are found in an article called: "Ancient DNA provides new insights into the history of south Siberian Kurgan people" by Christine Keyser. The genetic map confirms that the Sarmatians in Poland (today the Poles), the Ossetians (Alans), Estonians, the Hungarians, the Finns, the Altayian peoples (not the Türks!) are all Old-Europeans and are genetically brothers. Also a genetic study by Ornella Semino called "The Genetic Legacy of Paleolithic Homo sapiens sapiens in Extant Europeans: A Y Chromosome Perspective" confirms that the highest occurrence of R1a in Europe is in Poland (Sarmatia) and Hungary. Why? Because they are the same people. They both descended from the Pazyryk culture. Note also that the Scythians had blonde hair and the Aryans didn´t. The occurrence of blond hair among the Iranian Aryans is because they mixed with the Scythians who also lived in North of Iran where the Old-European N1a is also found.
Archeology: The Scythian archeology is the same as of the other Finno-Ugrics i.e. Old-Europeans.
Anthropology: The anthropology confirms that the Scythians were Caucasoids and also many of them were Euro-Mongoloids due to mixing, just like the Hungarians and the Avars. Moreover according to a Hungarian anthropologist, the anthropological features of the Sarmatians were the same as of the Hungarians. An another Hungarian anthropologist from the Hungarian Academy of Sciences also said that anthropological features of the Avars and Hungarians was also the same so they are not distinguishable. No surprise. All these three peoples descended from the Pazyryk culture as it is confirmed by their genetics, archeology, anthropology and culture-anthropology.
Linguistics: The Scythian-Iranian theory follows the logic: Ossetians speak the Northern branch of the Iranian language, Ossetians are Alans, Alans are Sarmatian tribe, Sarmatians are akin to Scythians, hence Scythians were Ossetian speaking, hence linguistically the Scythians belonged to the Iranian branch of the Indo-European family of languages. A brilliant logic that, in the not less brilliant words of V.I. Abaev, "ends the light-weighted and irresponsible speculations on Scythian material which do not have anything common with a science" ( V.I. Abaev, Ossetian language and folklore, 1949, page 148). The theory, created and fanned by a coincidence of German racism and Russian national-imperialism, took hold and hardened in the Indo-European science to a status of axiom, any facts notwithstanding.
The Scythians spoke an agglutinative language with Iranian lexicon (V. I. Abaev): an agglutinative language cannot be Indo-European, regardless of its lexicon: lexicon is easily changed or contaminated, word by word, with time; but changing the agglutinative structure of a language requires a sudden entire language replacement, which did not occur.
Many Scythian words are clearly connected to Finnish, Estonian and Türkic (Altayian) languages. Remnants of Finno-Ugric languages have been found also in Tocharian.
A brilliant comment from an unknown person: The theory about the Iranic-Sakas is based exclusively on an interpretation of a limited number of names, that can also be perfectly be interpreted based on Slavic, Turkic and even some attempt to use Finno-Ugrian languages. It is "presumed" that Sakas spoke an "Iranic language." But how can it be proved in any way, if we don't have any remnants or inscriptions in this language at all, except Issyk-Kul inscription for which there are several possible explanations? Regarding Ossetian language it has 40% of Turkic, 20% of Iranic and 40% of Caucasian vocabularly and it's agglutinative language like Turkic or Caucasian languages. There are some limited "Iranic" grammar elements in it which are exagerrated to the point of calling it "Iranic." But based on what? It can be called Turkic or Caucasian by the same token!! After all, is there any Indoeuropean agglutinative language? I don't think so. The classification of Ossetian is clearly flawed. And, BTW, the way Ossetians speak and pronounce the words clearly sounds Turkic, nothing even close to Iranic languages... If it is so, then why can one claim that their language is "Iranic" may be it's Caucaisan or Turkic complicated by some Iranic elements? Some Caucasians believe Ossetians are a product of the mixture of some Iranic speaking soldiers of Tamerlan and the locals...
Important note: Linguistic comparisons are irrelevant when searching the origins of peoples because languages change much faster than the genetics do.
Culture-anthropology: The Scythians buried their dead in Kurgans just like the Hungarians did. The Aryans burned and never buried their dead.
The Scythians sacrificed horses just like the Hungarians did but the Aryans never did.
The Scythians unlike the Aryans or "Indo-Iranians" had women warriors or Amazons exactly like the Hungarians. Hungarian women also fought in the battle for the Egri vár.
See also a study called: "Mamas of Pokrovka Sarmatians Preliminary results of mtDNA study" by Joachim Burger.
Some more information:
“The bearers of the Middle Bronze Age Andronovo culture were strongly associated with the Indo-Iranians: this is utter nonsense from the Propaganda Ministry, in the framework of the Scytho-Iranian theory advocated by V.I.Abaev that Lamberg-Karlovsky does not advocate”. (Source: http://s155239215.onlinehome.us/turkic/turkicsite.htm)
“Russian and Central Asian scholars working on the contemporary but very different Andronovo and Bactrian Margiana archaeological complexes of the 2nd millennium b.c. have identified both as Indo-Iranian, and particular sites so identified, are being used for nationalist purposes. There is, however, no compelling archaeological evidence that they had a common [Indo-European] ancestor or that either is Indo-Iranian". (Source: Michelangelo Naddeo, Genetics)
"There is no evidence for the Scytho-Iranian theory of Abaev".
- C. C. Lamberg-Karlovsky (Source: Michelangelo Naddeo, The Huns and the Alans)
"How can you associate the Indo-Europeans to the Andronovo, Abashevo, Syntashta, Arkaim, Pazyryk, Tagar, Tarim Basin cultures, whose archaeology (my additon: and anthropology) is 100% Finno-Ugric since 5000-3000 years ago?" (Source: Michelangelo Naddeo, Open letter to Victor Mair)
NOTE: R1a can in no way be connected to the so-called "Indo-Europeans/Aryans".
Much more proofs and informations can be found on the website: michelangelonaddeo.com and in the books which are for sale on the same website.