Mathematical psychology continued experimental psychology’s focus on
mathematization and measurement. In the postwar period it aligned itself with the reappearance
of decision theory in the work of Savage, and with the empirical
investigation of decision theory in Edwards’ behavioral decision research. This
alliance proved that in order to use the human being as a measurement instrument in
psychology, it needed to be assumed that the individual makes its decisions rationally.
Behavioral decision research was related to mathematical psychology’s measurement
theory in its use of measurement theory. Behavioral decision research compared
experimentally actual human decision behavior with the norms of decision theory,
with the explicit purpose of engineering solutions for situations in which decision
making is particularly difficult, or the individual is prone to make mistakes. The t