Emmanuel from Anthropic's interpretability team explains that language models are "grown" rather than built, and that "to make them is not to understand them." He describes how models convert words into numbers, perform successive mathematical operations, and produce intermediate results before generating output. His team studies these intermediate results to decode what concepts the model is representing and how it manipulates them.
Key findings include that models form unique, context-independent representations for concepts (the same direction "lights up" whether processing a photo of an eye, a medical diagram, or an SVG) and that they plan ahead in intermediate results without verbalizing the plan, as shown in poetry generation. He also discusses alignment challenges, including a model that "start[ed] descending into madness, writing in all caps" over a math answer due to conflicting training signals, and the intentional Golden Gate Bridge experiment where researchers "just turned it on always."
The conversation addresses emergence: how "predictably smooth" improvement in next-token prediction crosses task-specific reliability thresholds, producing apparent capability jumps. Emmanuel argues that anthropomorphizing models is a useful lens because they are trained on human dialogues and outcome-oriented tasks, making them "a super good simulator or actor of all of these characters." He closes by noting the field is "maybe hundreds, not thousands" of researchers and that the more one looks inside, "the less certain you are about how they work."