I now know the sting of rejection when a child strains to be soothed by the other parent. I had to learn the art of Skypeing-with-toddlers, building up an assortment of props and sending little videos of myself every day to kick off the conversation. (“Mommy ate strawberries, what did you eat?”)

But I also tasted the freedom of not being responsible on a day-to-day basis, of being the scarce parent, the fun-time parent rather than the one in charge of brushing teeth or disciplining.

This was an entirely unscientific experiment, but here is what we learned: Responsibility and time, not gender, determine the depth of the bond with a child.

When Dad Becomes the Lead Parent – NYTimes.com.