Contact Group Mail uses Work Email… How do you set it to Home Email?

I have a group of family and friends to whom I send a couple of jokes a week.  Contact Groups defaults to Work Email which is not appropriate, but I don't see any way to set the default email in the individual user's identity or in the Group. I see no global preference. How can you set the default email to Home email?    If you can't, this is a major oversight.