Q: What was Ivan Pavlov's nationality at birth?  

Ivan Petrovich Pavlov ( 26 September 1849 - 27 February 1936) was a Russian physiologist known primarily for his work in classical conditioning.

From his childhood days Pavlov demonstrated intellectual curiosity along with an unusual energy which he referred to as "the instinct for research". Inspired by the progressive ideas which D. I. Pisarev, the most eminent of the Russian literary critics of the 1860s, and I. M. Sechenov, the father of Russian physiology, were spreading, Pavlov abandoned his religious career and devoted his life to science. In 1870 he enrolled in the physics and mathematics department at the University of Saint Petersburg in order to study natural science.