For the longer term, researchers have found a correlation between formula and an increased incidence of diabetes and obesity, but many argue that the connection is almost impossible to tease apart from the broader socioeconomic environment a baby is raised in .

Whatever the scientific reality — and by this point I was not an unbiased reader — the research put my anxieties to rest enough that I could start to appreciate what the formula was doing for my relationship with my son.

I had heard about the shot of endorphins that mothers got during feeding. While I don’t know about the physiology in my own case, I can say that I came to associate feeding my son with a profound sense of well-being — and I assume the feeling was reciprocal. Now that I had tasted this, it seemed a little unfair that only my wife would have gotten to enjoy it.

As the weeks went by, I noticed a subtler but deeper change in my relationship to my son.

Now when my son cried in the night, or out in public, I instinctively started toward him. Before this, my wife had been the first responder because we assumed that he probably needed to be fed. Now, I was just as capable of feeding him as she was. This meant that I not only fed him, but learned about all the times when he wasn’t actually hungry but needed a burp or a clean diaper, or something else that we couldn’t figure out, but that was part of the essential mystery of parenting. I came to understand his rhythms and needs.

This gave me a sense of agency and confidence as a parent that I became particularly aware of when friends, who were fathers of breast-fed children, looked nervously to their wives when their children cried. I noticed how the inability to supply milk gave many men a sense that they were also less capable of doing other parenting tasks that have nothing to do with milk (I’m thinking of you, guy at the airport who was scanning his phone while his wife chased after their toddler during the entire flight delay).

Of course, many breast-feeding women also pump, so their husbands or other caregivers can offer the baby a bottle. But the demands of pumping make it hard to divide responsibilities equally.

I don’t want to make it sound as though being available for every feeding was all sunshine and cherries. I suddenly had to wake up a lot in the middle of the night.