Fat,sex, class,adaptive flexibility,and cultural change

In modern industrial nations, the traditional positive correlation between female body fat and social class has turned strongly inverse, thinness in women is admired and plumpness is a handicap. This recent reversal of what had seemed to be stable aspects of human nature is analyzed as a potentially adaptive response to two ecological novelties: chronic food surplus and the breakdown of barriers between men's and women's work, which, together, may have made thinness helpful to women competing for status and resources in both mating and job markets. Whether status and resources still promote long-term Darwinian fitness is an open question. Progress in understanding the unique properties of the human mind depends on widespread recognition that the mind has been designed by natural selection to seek and sometimes find adaptive solutions to the novel problems we ourselves create. Adaptive flexibility and cultural change are two sides of the same coin.