request for addition to R-int

http://cran.r-project.org/doc/manuals/R-ints.html#R-coding-standards

 gives detailed advice on how to set the indentation level for
C code to 4, but it took me a bit of poking around in the archives
to find the

(setq ess-indent-level 4)

incantation for getting the R indentation right as well.

I'm confused.  Doesn't the suggested code 

(add-hook 'ess-mode-hook
               (lambda ()
                 (ess-set-style 'C++)
 ...

implicitly set ess-indent-level to 4?  At least for me, using the
suggested code gives indentation steps of 4 in R code.

Bj?rn-Helge Mevik