How do bonds between fathers and offspring relate to bonds between romantic partners? What aspects of the father-infant attachment are uniquely human? These questions have been the subject of much research from historical, biological, and evolutionary perspectives. We know that committed partnerships contribute to human happiness and well-being and that they also sustain the physical and mental health of its members. These positive effects of social bonds have been documented with regards to the adaptive psychological development of the partners’ offspring as well. Life span developmental research in humans shows a strong association between the relationships of children with their parents and the quality of these children’s marriage when they become adults. Still, despite the undisputable benefits of stable, enduring social relationships, very little is still known about the expression of father-infant bonds in humans and non-human primates. In fact, committed paternal care remains a paradox among mammals, humans included, because father uncertainty due to internal fertilization and female-biased investment in the young through pregnancy and lactation ought to discourage males from investing in putative offspring.