sl and preservice teachers

I am researching teacher education and the use of service-learning.  I am investigating use of service-learning to promote both civic engagement and moral development.  I've found some research showing education majors scoring lower than other majors in moral development, so am interested in any databases or studies specifically addressing education majors.  Has anyone done any research on this?

Thanks,
Sally Jackson
Literacy Serve and Learn
Graduate Assistant
Bowling Green State University