Kortlandt assumed that the similarity can be attributed to areal factors .
Kortlandt thought of Indo - European as a branch of Uralo - Altaic that was transformed under the influence of a Caucasian - like substratum .
Assuming that the similarity can be attributed to areal factors , Kortlandt thought of Indo - European as a branch of Uralo - Altaic that was transformed under the influence of a Caucasian - like substratum .