Attachment bonds are a defining feature of mammals. A conceptual framework on human attachments is presented, integrating insights from animal research with neuroimaging studies. Four mammalian bonds are described, including parent-infant, pair-bonds, peers, and conspecifics, all built upon systems shaped by maternal provisions during sensitive periods, and evolution from rodents to humans is detailed. Bonding is underpinned by crosstalk of oxytocin and dopamine in striatum, combining motivation and vigor with social focus, and their time sensitivity/pulsatility enables reorganization of neural networks. Humans' representation-based attachments are characterized by biobehavioral synchrony and integrate subcortical with cortical networks implicated in reward/motivation, embodied simulation, and mentalization. The neurobiology of love may open perspectives on the 'situated' brain and initiate dialog between science and humanities, arts, and clinical wisdom.