After 1935 her son Wolfgang worked in the movie industry in Moscow . He is described by one source as a follower of Nikolai Bukharin , however . This may or may not be why he was caught up in the purges of the time , disappearing , along with many other German political refugees in Moscow , in 1938 . Her elder son was building a career as a notable Gestalt psychologist , by this time based at Swarthmore College near Philadelphia , and a couple of hours by train from New York . There are sources indicating that he had nevertheless been struggling with mental health issue of his own for some year : early in February 1940 , shortly after his 37th birthday , following a series of " nervous breakdowns " , Karl committed suicide . His mother was badly affected . She was nevertheless able to agitate successfully to obtain a US residence permit for her husband , at this point living precariously in semi-occupied France . He arrived " stateside " in September 1941 . By this time Käte Duncker had obtained a job teaching German at a high school
purges of the time
Great Purge
Käte Duncker