The notion that humans form socio-emotional bonds with other people is an underlying assumption of much archaeological work on social life in the past. Yet we have been slower to recognise the emotional role of non-humans. From our relationships with objects, animals, religious beliefs and important places, we can gain intense, palpable feelings of security, which impact our cognition and social behaviour, and which provide a wealth of benefits to our mental and physical health and well-being too. In this paper, I discuss how the psychological theory of attachment may provide useful insights into a variety of interpersonal and non-human socio-emotional relationships, helping us to understand why and how humans form attachment bonds. I will also discuss the significant, yet understudied, role played by so-called ‘compensatory’ attachment figures such as companion animals and cherished possessions. Attachment theory provides a simple, yet useful, framework with which to think about bonds in the past, and so allows us to broaden our conception of who—and what—plays an important role in our social and emotional lives. This has broader relevance in the modern world for how we think about concepts such as emotional resilience, material relationships and the significance of our social lives. Humans are, at heart, intensely social creatures, and thinking about the nature of our social lives and the role of attachment provides exciting insights into life in the past.