Narcissists and the single-mindedly ambitious thrive in Hollywood for the same reason that successful actors and filmmakers are disproportionately neglectful, if not often outright abusive, in their personal lives. From vaudeville impresario Ethel Milne’s relentless “momaging” of Judy Garland — professionally dazzling, personally ruinous — to today’s alleged deadbeat A-list parents, such as Brad Pitt, the entertainment industry is full of extraordinary talent and cautionary tales of family dysfunction.