and concerns about the impact on their own children.
I know a family that took in a foster kid (maybe several?). They finally had to give it up because the kid was out of control and endangering their own kid. They really wanted it to work and they really tried. IMO they kept the foster kid long past the time when they should have.
Not every case is like that. But people need to be careful.
True.
Though WHEN the father particularly but also the mother are quality solid parents, well bonded to their natural children--the risk is relatively minimal. Modern life, however, seems to leave little time for such quality parenting. Though quality parents still, somehow, manage to carve out the necessary time.