A psychiatrist, Stern was intrigued by a colleague’s study that showed kittens could learn things on their first day of life. Surely that would apply to humans, he thought, so he studied the interaction between babies and their mothers. Thanks to videotaped interactions, which he could slow down for frame-by-frame analysis, he described the “motherese” he observed — the communication that mothers use to read even tiny signals from their children. He rejected Freud’s “phases” (such as “oral”): a child’s development is much more subtle, with a series of overlapping and interdependent stages of development that are increasingly sophisticated. Also, he found, even seemingly minor incidents were integrated into memory, and could show up later. In adults, he studied the perception of time. He found that it took people a good hour to describe all the thoughts that went through their heads in a 30-second span over breakfast. Dr. Stern died in Geneva November 12, from heart failure. He was 78.
From This is True for 18 November 2012