Every experience we have leaves an imprint in our brains. Physical and social experiences can change the brain. We refer to experience because environment (1) is a catch-all term and (2) suggests that humans are passive entities. We know that this is not the case, as carefully discussed almost a century ago by Louis Leon Thurstone (1923) during the behaviorism academic tidal wave that simplified all human behavior as comprising nothing more than responses to stimuli without any role for motivation, intention, or any other nonobservable construct (Watson, 1919). With today’s historical perspective, behaviorism was much less generalized and influential than usually discussed in textbooks about the history of psychology (Braat et al., 2020). Thurstone’s active view is illustrated in the bottom of Figure 7.1. Critiquing the passive approach of behaviorism, he wrote in “The Stimulus–Response Fallacy in Psychology,”