There are several key differences between the codes of ethics developed by the American Psychological Association and the Canadian Psychological Association. This paper tells the story behind the key differences between the U.S. and Canada codes. It starts with an introduction to the two countries and a brief history of what led up to the American Psychological Association’s (APA) decision to develop the world’s first ethics code for psychologists. This is followed by a description of the development process used by (...) APA, and the reasons why the Canadian Psychological Association (CPA) originally adopted the APA code but subsequently chose to develop its own “made-in-Canada” code of ethics. The key differences of the CPA code, the cultural, legal, and philosophical contexts that help explain the rationale for those differences, and why the differences have been maintained are discussed. In particular, attention is given to the CPA code’s strong focus on: (a) the concept of a contract with society; (b) aspiration vs. enforcement; (c) ethical reasoning and decision making; and (d) organizing standards around ethical principles. (shrink)