Making sense of the personality of Hakan in Diaz's In the Distance

Trying to get a sense of the personality of Hakan, the protagonist in Hernan Diaz's novel In the Distance. We know from the outset that he and his brother - seemingly both teenagers? - set off from their native Sweden, ca 1880 I think, headed for NYC, but they get separated en route and Hakan lands in SF, then sets off east, against the flow of migration, to find his brother, Linus, in NYC. First of all, if Diaz gives us any significant family background of the two I can't remember it; in any event, of the course of the (first two-thirds) of the novel we learn little or nothing about Hakan's family and youth. He is an amazingly non-introspective character, in some regards, and in others he's thoughtful and almost philosophical. I have to think of Hakan as perhaps on the autism spectrum or living with some degree of retardation. Just the idea that he expects to cross the country to New York and that he can somehow easily find his brother in the city suggests he's naive to an extreme degree. He's also painfully shy, especially around women. In what seems to be the climactic scene of the novel he almost single-handedly fights off an attack on a group of settlers whom he's traveling with, kills several of the attackers, and then feels such guilt and remorse about doing so that he leaves the group and heads off alone. Over the course of his tortuous journey he continues to think of himself as a pariah - rather than as a hero. Despite his extreme social awkwardness, he turns out to be a quick study when it comes to nature and medicine; he's extremely resourceful in keeping himself fed and free from fatal exposure while traveling alone across deserts, ranges, plains - and he learns from a companion the rudiments of surgery - well enough to perform delicate operations on a young boy and on his horse. Putting all this together, to the extent that his character makes sense at all, he seems like a genius with severe social anxieties, an adept at survival but an incompetent at the basic skills of community and social life.