One-way trust between 2012 R2 forest root and a child domain

I understand that in a 2012 R2 forest a two-way trust is automatically created between the root and each child domain.  Is it even possible to change the root - child domain trust to a one-way trust?  And if it is possible are there pros and/or cons to using a one-way trust between the root and the child domains?

Any advice/comments/experience with the above scenario would be greatly appreciated.

Thanks,

J.