And if so, would this work for female fathers as well?
As reported in The Economist (a tip o' the nib to lesbiandad.net for the link and through her, Katherine Ellison, author of The Mommy Brain) a study conducted by Dr. Elizebeth Gould found that parental behavior on behalf of marmosets actually changed the male's brain. Male marmosets "carry their babies for more than half the time during the offsprings's first three months, passing them to the mother only when the babies need to be fed." This resulted in an increased number of nerve cells in the brains that suggest possibly more activity in the father's brains than in those of the non-fathers.
I can tell you that although my back has been much strengthened (and our baby bjorn worn out) over these past 10 months as Big has grown to an astounding 27 pounds, my brain feels, in contrast, weakened.
What does this mean for human fathers you ask?
Craig Kinsley of the University of Richmond, Virginia, who did the work with rat mothers, speculates that Dr Gould's new findings may reflect human behaviour quite closely. "There is a lot of interest in the idea that having children forces responsibility on males in many respects. If you consider that the prefrontal cortex plays a major role in planning, judgment and the anticipation of the consequences of behaviour, you could make a clear argument that the changes in that part of the brain would be involved with judicious attention toward offspring."