[4][5] Timberlake earned his PhD in experimental psychology at University of Michigan in 1969 under the supervision of David Birch.
[8] Timberlake was the key mover behind the establishment of the interdepartmental animal behavior programme and Center for the Integrative Study of Animal Behavior (CISAB)[9] at Indiana University (co-founded with biologist Ellen Ketterson).
Timberlake established (with co-chair, James Holland) an ethics committee to oversee animal research on the Bloomington campus (the ancestor of today's BIACUC, Bloomington Institutional Animal Use and Care Committee).
Timberlake also established research ethics courses and assured that they remained a part of core curricula of the animal behaviour programme at Indiana University.
Timberlake was a fellow of the American Association for the Advancement of Science,[16] was a fellow and held multiple offices of three APA (American Psychological Association) divisions, and served as president of APA's Division 6.