Many of the scholars represented in this collection have faced barriers or obstacles that they need to overcome. Some, especially scholars whose essays appeared in the previous section, faced barriers as a result of entering the United States as immigrants. Others faced barriers because their parents, first generation settlers in the United States, were unfamiliar with the language, customs, and social demands of their new country. The children of their parents, several of whom became scholars whose autobiographies appear in this issue, had to navigate the unfamiliar terrain and negotiate a sense of self within an often-hostile environment. Still other scholars faced obstacles when a parent or a spouse died and they had to make unexpected decisions. Finally, some scholars witnessed their life goals or academic careers change dramatically when genetics or disease altered their plans. Most were shaped, to some extent, either by events they could not control or by forces in the larger society that set parameters for the options available. As such, their essays illustrate how a person's life and work are, in part, intertwined with and products of many larger forces that define the essence of "cohort effects."