[5] The data that they recorded included reactions, babbling, the ability to recall events, lying and moral judgment.
In addition to the detailed diaries of language development, the Sterns systematically recorded one-on-one sessions with each child.
It has been argued that her most important contribution to their joint studies was the immensely detailed diaries she kept for 18 years, as Clara was the one who bore that burden, not William.
The remaining books - Regarding and Representing, Child's Play, Will and Emotional Life, Thinking and Beliefs - were never published and Clara and William Stern never worked together on a joint publication after that.
However, in 1914, William Stern published a textbook titled Psychology of Early Childhood and he acknowledged his wife's contributions to the work even though she did not appear as a co-author.
He adopted the pseudonym Günther Anders and published works advocating for world peace and opposing nuclear weapons.
The youngest Stern sibling Eva was involved with the Youth Aliyah movement which rescued Jewish children from the Nazis.
With the domination of governmental power in Germany by the Nazis in 1933, Jewish scholars were systematically removed from their professional positions and William Stern was forced to give up management of his psychological institute and his functions on all committees at the University of Hamburg.
Warned by their 31-year-old son Günther that Hitler's ultimate aim was the extermination of the Jews, the Stern couple went into exile abroad, first to the Netherlands and then to the United States.
Duke University in Durham, North Carolina offered William Stern a professorship in the Department of Psychology that ensured the couple's livelihood.
The eight busts alongside that of Clara Stern are those of (in alphabetical order) Paul Broca, Karl Bühler, F. C. Donders, Roman Jakobson, Edward Sapir, William Stern, Carl Wernicke, and Wilhelm Wundt – all widely known and highly respected historical luminaries, and all males.