A cast of thousands: Coauthorship and subauthorship collaboration in the 20th century as manifested in the scholarly journal literature of psychology and philosophy

We chronicle the use of acknowledgements in twentieth century scholarship by analyzing and classifying more than 4,500 specimens covering a 100-year period. Our results show that the intensity of acknowledgment varies by discipline, reflecting differences in prevailing socio-cognitive structures and work practices. We demonstrate that the acknowledgment has gradually established itself as a constitutive element of academic writing, one that provides a revealing insight into the nature and extent of sub-authorship collaboration. Complementary data on rates of co-authorship are also presented to highlight the growing importance of collaboration and the increasing division of labor in contemporary research and scholarship.