Thank you, Laura. Your comment brings a note of common sense to all of the psychological speculation. (I wouldn't term Lion's musings "claptrap," since anyone would be affected by such an accusation, but speculation it remains.) You are right: if Bix had molested children as an adult, it seems most likely we would have heard of it. One case in point is Ralph Berton's memoir, which I felt was rather egocentric, being more about the Berton brothers than about Bix himself. Ralph describes what could be (and was by brother Vic) called a "crush" on Bix, a thirteen-year-old's adolescent admiration that was almost worshipful. If Bix had had any such inclination toward children, wouldn't that have been an opportunity? And would not Ralph have written about it? (I know--this is speculation on my part.) But Ralph describes that during the time Bix stayed with the Bertons he did nothing more than snore in Ralph's bed, remarking offhandedly that the "youngest child's bed is always the guest room."
Thank you, Albert, for the extended Lion quote. I noticed again in the paragraph ahead of Wolfe's quote were, as I mentioned, certain verb forms which indicate that what follows is speculative analysis on his part. Speculation is acceptable in biographical writing if stylistic signals that that is what it is. Sudhalter talks about Bix's personality as well, but he indicates in his biography and in the preface to Lost Chords that he intends to alternate factual information with interpretation and analysis and uses "writerly" devices to indicate where he shifts from one to the other. Other authors such as James Lincoln Collier speculate about Bix's "problem" as rooted in various aspects of his personality. Here on the Forum we have discussed, in addition to chronic, early onset alcoholism, other physiological causes--depression, the toxicity of bootleg gin, ADHD, etc,--all more or less plausible possibilities, but obviously not clinical diagnoses that we can now make.
Part of the fascination with Bix is the disjunction between his masterful musical gifts and the increasing disorder of his ability to protect those gifts in daily life. I don't think there is subsequent evidence that the Ivens episode was a significant cause of that. Still, it happened and it is out there in the public record now, so biographers will have to cite it or be accused of bias.