I wanted less dark shadows and when I asked about it, I was told to go into the parameter dials for each light and lower the shadow intensity.  It works really well.  I usually change it to  between 60 and 80.  If you want darker ones, try increasing the value.

You can also go into the properties area of the parameter dials and turn off shadows for certain items/parts.  I always turn off cast shadows for hair that is neck length or longer as I don't like the black voids at the neck that long hair tends to have with shadows turned on.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi