I did some research on brother/sister incest for a play I
wrote, "Good Blood and
High Standards". Brother/sister incest is pretty common,
at least in circumstances where the kids have unsupervised
time together and/or sleep in the same room.
However, most of it is between siblings near in age and is
exploratory in nature-- "playing doctor" -- and is forgotten
or repressed when the sibs mature. The incidence dwindles
when kids are raised under constant adult supervision -- as
they usually are in the prosperous middle-class families who
were the subjects for psychoanalysis. Not much lit on it,
and the stats are from broad surveys rather than clinical
practice. Victims seldom show up in clinical practice. You
do see in the tabloids cases of brother/sister couples who
have assumed new identities in order to live as if married,
if they happen to be discovered and prosecuted.
I was an "only" till age 8, and baby brother never interested
me much, but I did hear of brother/sister sex play from friends,
mostly farm kids from large families who fooled around in
the barn. These kids seemed otherwise normal to me.
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