Primogeniture -- ie the practice of the eldest son inheriting the bulk of the estate -- must have caused some uneasy relations between older and younger brothers, but on the whole JA doesn't go into much detail.

Her two Mr Knightleys appear to get on very well indeed: there isn't even a suggestion that Mr John is jealous of Mr George, not even when his brother marries and is likely to produce an heir to cut young Henry out of inhering Donwell.

There's a bit of edge between Tom and Edmund Bertram, but in his illness Tom wants only Edmund to look after him, in circumstances which might get less scrupulous younger brothers eying the laudanum bottle.

Even the unpleasant Robert Ferrars doesn't seem to mind his younger brother status: he laughs at his elder brother, but he doesn't seem to gloat when the positions are reversed.

There's a slight complaint from Col. Fitzwilliam, but we never see his elder brother, so we don't know anything about the relation.

So, was this relatively harmonious relation between older and younger brothers common, was JA basing it on her own family, or was she just not letting her pen dwell on guilt and misery?