I'd like to talk about biographies, particularly how historians should write about aspects of their subjects' lives that don't have much documentary evidence.

I'm currently reading through H.W. Brand's new biography of Ronald Reagan and have been thoroughly unimpressed. While the entire book is disappointing, I think the worse sections are on Reagan's pre-presidential life, which Brands spends roughly 250 pages on. His treatment of this part of Reagan's life is very superficial. In particular, several chapters exclusively cite only Reagan's two memoirs, and there is little to no actual analytical engagement with these sources. Essentially what Brands has done is re-tell the story of Reagan's pre-presidential life as Reagan has already told it before. Perhaps worse, since the documentary evidence on Reagan's early life is so sparse, Brands seems to over-emphasize the later significance of those few early life experiences that we do have reference to. For instance, he stresses that Reagan's involvement in local church plays at the age of 6 and 7 likely laid a foundation for Reagan's lifelong obsession with holding the captivation of a large audience.

Because of a lack of documentary sources, Brands tries to fill in the pages with a history of American society as it was throughout Reagan's life. Here again, though, the analysis is superficial. Brands gives bare-bones accounts of the Depression era, the New Deal, WWII, and the civil rights movement, but he fails to relate these events to the development of Reagan as an individual. The book's structure therefore becomes fragmented because there is no linkage between how American society influenced Reagan.

So, how should biographers handle aspects of their subjects' lives when there is little documentary evidence? Do they do as Brands has done and only discuss it superficially and perhaps draw conclusions that aren't borne out by any documentary evidence--in other words, does the biographer "fill in the gaps"? Or is it perhaps best to leave it out all together?