auto-insert is a variable defined in `autoinsert.el'.
Its value is

Controls automatic insertion into newly found empty files.
Possible values:
nil do nothing
t insert if possible
other insert if possible, but mark as unmodified.
Insertion is possible when something appropriate is found in
`auto-insert-alist'. When the insertion is marked as unmodified, you can
save it with C-x C-w RET.
This variable is used when the function `auto-insert' is called, e.g.
when you do (add-hook 'find-file-hook 'auto-insert).
With M-x auto-insert, this is always treated as if it were t.

You can customize this variable.