This is what Ned Polsky had to say about Beats and Hipsters in the chapter 'The Village Beat Scene: Summer 1960'.
Until recently 'hipster' meant simply one who is hip, roughly the equivalent of a beat. Beats recognized that the hipster is more of an 'operator' - has a more consciously patterned life-style (such as concern to dress well) and makes more frequent economic raids on the frontiers of the square world - but emphasised their social bonds with hipsters, such as their liking for drugs, for jazz music, and, above all, their common scorn for bourgeois career orientations. Among Village beats today, however, 'hipster' usually has a pejorative connotation: one who is a mannered show-off regarding his hipness, who 'comes on' too strongly in hip talk, etc. In their own eyes, beats are hip but are definitely not hipsters.
And in case you've wondered where the term 'hip' comes from...
The few Village beats with any opinion suppose it comes from the 'hep' of early 1940s jive talk. Actually 'hep' and 'hip' are doublets; both come directly from a much earlier phrase, 'to be on the hip', to be a devotee of opium smoking - during which activity one lies on one's hip.