I think you have to parent both the head AND the beard to something and scale THAT in order for both parts to scale in unison. That's why I usually parent the whole character - including clothes - to the Poser ball (any prop can be used of course)

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.