Why does Holden feel the need to lie?

is a very
sensitive person, which could be
seen as his core "problem," and as an adolescent, he
is also struggling with
issues of identity. He most often lies, therefore, to protect other
people
emotionally, and then to protect himself emotionally.

For instance,
as
the novel opens, he has been asked to leave Pencey because he is failing
too many classes. His
history teacher, , sends him a note asking him to come
say goodbye. Holden visits, and he lies
to protect Mr. Spencer's
ego:

Well, you could see he
really felt
pretty lousy about flunking me. So I shot the bull for a while. I told him I was
a
real moron, and all that stuff. I told him how I would've done exactly the
same thing if I'd
been in his place, and how most people didn't appreciate
how tough it is being a
teacher.

Holden is actually very kind to Mr. Spencer. He
has to get away, though, as
it is uncomfortable for him to be there, so he tells what we would
call a
white lie and says he has to be somewhere else....