Study of self reported emotional closeness with best friend (from a 2002 questionaire of a 1997 longitudinal study) found no difference between black men and black women, and a small gap for Hispanics, no economic differences for white women, and a large gap for wealthy white men, who seem to be an outlier demographic group, in this variable at least.
It's not a really strong data set (the survey is all of people born between 1980-1984, surveyed in 2002, and they threw out AAPI responses because there were only a few of them) but it suggests that male loneliness might be an artifact of a culture common among the American economic elite.
