Popular geneaology is the province of snobs seeking to secure their own social popularity. No comfort for them in this readable, albeit discursive report on kinship in general and geneaology in particular. Take the guardians of file nuclear family, that holy trinity of father, mother, and children. In the history of most of the world, it seems, father has been an unstable unit of kinship. His role is strictly ""peripheral."" That leaves mother and children as ""the only real continuity in any society [because] motherhood can be verified by witnesses. . .paternity is the great unknown. . ."" Those at pains to advertize, often through their middle names, family connections to distinguished personages or lineages are just kidding themselves, genetically speaking. The number of genes held in common with any single ancestor of more than three generations back is infinitesimal; complex traits such as intelligence and behavior are the ""least likely to persist in a family for any length of time."" So much for the D.A.R. The astonishing ""mathematics of descent"" dictates that everyone's pedigree is diamond-shaped; it widens to a point centuries ago when one's ancestors were approximately five-sixths of the world's population, then narrows back toward the presumed original father and mother. However, thanks to cousin intermarriages, ""pedigree collapse"" occurs in many lines, most conspicuously among the so-called well-born, such as Prince Chares, who in the 17th generation of his pedigree has only about 23,000 ancestors, not the 65,536 progenitors others theoretically enjoy. But marrying cousins isn't all that unusual--or disreputable. ""If we could only get into God's memory,"" anthropologist Robin Fox is reported to say, ""we would find that 80 percent of the world's marriages have been with second cousins."" Admittedly leaning heavily on Fox and a couple of other academic sources, the author traces kinship from its earliest signs in prehistoric graves to the rise of modern individualism and the current re-kindled fascination with heritage. In one chapter, he visits Salt Lake City and its Genealogical Society where Mormons are gathering and verifying the names of all the dead of history. So far about a billion and a half names (of the six or seven billion persons who ever lived) are on file in a mountain vault that lends the book its title. Except for its psychology, which is only faintly grasped (C.G. Jung is mentioned in passing as ""Carl J. Jung, who explored the human love relationship in great depth""), this compendium is an avalanche of nifty facts that should make great dinner-party chatter: ""Of the 1,286,556 surnames on the Social Security roles [sic] of 1974, 448,663 were single occurrences."" What's in a name? More than you thought.