W William Timberlake Timberlake Evan Arnet Indiana University Bloomington, Bloomington, IN, USA William “Bill” Timberlake (1942–2019) was a comparative psychologist and animal behavior researcher who achieved key experimental and theoretical findings through his integration of ecology and ethology into learning theory (Arnet 2019). He explored a broad array of topics but is best known for his work on response deprivation and reinforcement and a leading version of the behavior systems approach to animal behavior. Timberlake was a frequent critic of strictly opera- tional approaches, and many of his contributions drew from his emphasis on the organism’ s motivational structure, and how this structure would lead to behavior in varying contexts. His work alongside other ecologically influenced psychologists like Michael Domjan, Sara Shettleworth, and Bennett Galef helped to expand comparative psychology into animal behavior studies more broadly. Nonetheless, throughout his career Timberlake emphasized the value of comparative psychology’ s focus on learning. In addition to his research contributions, Timberlake was a founding member (alongside the biologist Ellen Ketterson) of Indiana University Bloomington’ s esteemed Center for the Integrative Study of Animal Behavior (CISAB). Much of this entry is informed by Arnet (2019), and the reader is referred there for a more detailed discussion of Timberlake’ s life and works (as well as the festschrift in Behavioural Processes, The Legacy of William Timberlake, of which it is part). Timberlake was born in San Francisco to William B. Timberlake and Louzelle Spradling Timberlake. He excelled in school and ultimately went to Pomona College where he studied psychology. He started his graduate work in psy- chology at the University of Michigan in 1964, where he gained a substantial background in neoHullian behaviorism. His advisors, David Birch and Edward Walker (added later as co-advisor), were both part of an innovative group of motivation researchers at Michigan. This group, while still studying motivation from a behavioral as opposed to physiological or neurological perspective, was nonetheless chal- lenging standard stimulus-response approaches (e.g., Birch and Veroff 1966). Rather than empha- sizing only the role consequences of actions played in motivating behavior, they increasingly looked to the existing motivations of the organism as playing an important role in the relationship between stimulus and response. Influenced by © Springer Nature Switzerland AG 2020 J. Vonk, T. K. Shackelford (eds.), Encyclopedia of Animal Cognition and Behavior, https://doi.org/10.1007/978-3-319-47829-6_2092-1