LeeAnne Harker and Dacher Keltner, both then at Berkeley, coded photographs from Mills College yearbooks and matched them against decades of follow-up data. As the study’s own history records, its participants were drawn from the senior classes of 1958 and 1960 at Mills College, a private college for predominantly white, middle-class women in Oakland, California. That is why a posed smile tends to look flat around the eyes and why a genuine one crinkles them. The posed smile is a motor-cortex action, something a person does; the genuine one is limbic, something that happens to them when they feel something. Photo by Melike B on PexelsWhat the paper does and does not supportTo summarise the reading carefully.