Moat of Johanna Kaplan's Other People's Lives are caught in transit from the old world (Poland) to the new (the Bronx, the Heights) but they have an animation all their own since in these six pieces (one novella, five short stories) she hustles experience with great mobility. So it is that Louise, a withdrawn girl with a sad history, joins the overextended family of a young woman who keeps muffling the past (perhaps the only certainty) and the present (a husband who is dying) in a babel of talk and activity -- ""other people's energies moving and rushing away."" Then there's the appealing ""Sour or Suntanned, It Makes No Difference"" to the city child unwillingly sent to see the trees in a summer camp, or the ""Baby-sitting"" of another teenager lucky enough to take care of the pajama-less infants of a prominent, egomaniacal poet. On the more serious side, there's ""Loss of Memory Is Only Temporary"" -- the young resident psychiatrist, like a ""stone,"" resisting the attachments of the past via the visitation of an aunt while dismissing the effects of E.C.T. . . . Since Johanna Kaplan has an attuned eye, ear and heart all going for her, she's starting out well ahead.