Lifespan is just one component of a species life history. To understand human longevity from an evolutionary perspective, it is important to consider the human species’ phylogenetic history and the evolution of the entire human life cycle. This chapter extends previous fundamental reviews in the light of recent findings, and with particular emphasis on the evolution of longevity of the human species. It first compares the primate life cycle to that of other terrestrial mammals, and highlights the evolution of the slow pace of life observed in primates. It then compares the life cycles of humans and other primates, emphasizing the peculiarities of the human life cycle. The chapter outlines the main theories explaining the evolution of these peculiar life history traits that occurred since the human-chimpanzee divergence, linking these to the evolution of human reproduction, ontogenesis, diet and cognition. It then emphasizes the pivotal roles of sociality and intergenerational transfers for understanding the joint evolution of the human life cycle, biology and cognitive, linguistic and social capabilities. Together, this finally allows a contemplation of the most probable scenario joint evolution of human reproduction, ageing and longevity.

Human mothers commonly receive help from others to support their children, an unusual reproductive system known as cooperative breeding. Because cooperative breeding is not a trait shared with other great apes, its emergence in the human lineage marks a significant departure in reproduction and parenting, which has far-reaching consequences for the life history, sociality, and demographic success of our species. This chapter first defines cooperative breeding and establishes those characteristics that distinguish humans from other cooperative breeders. To unravel the evolutionary puzzle of cooperative breeding, the benefits of helping to mothers and offspring, why helpers help, who helps, and what helpers do are then reviewed. The discussion then turns to the question of why humans become cooperative breeders. Because humans provide food, shelter, and protection not just to infants but also to juveniles, humans expand the range of helping behaviors beyond those observed in other cooperative breeders, which has implications for many other aspects of sociality. Cooperative breeding has much to offer as a framework for conceptualizing the cooperative nature of humans and to explain our derived life history of early weaning, high fertility, and the long developmental period during which juveniles benefit from both receiving and giving help.

For most of human evolutionary history our species lived as hunter-gatherers; hence, much of our cognition and behaviour is adapted to this way of life. Given the magnitude of the sociocultural, economic and lifestyle changes experienced by Homo sapiens over the last 10,000 years, in particular the last several hundred years, aspects of human psychology may be maladapted to modern ways of life. This process of maladaptation following changes in the physical or social environment is referred to as ‘evolutionary mismatch’ and has been hypothesised to contribute to the high prevalence of mental disorders in industrialised societies. However, very few studies have examined the prevalence of these pathologies among contemporary hunter-gatherer populations; thus, empirical support for such diseases of modernity hypotheses is lacking. In this chapter, we review the limited existing research and theorise about the key differences between hunter-gatherer and industrialised societies that are likely to have profound implications for mental health. Specifically, we contrast the strong social support networks, egalitarianism, explorative modes of learning, sensitive child-rearing practices and present orientation of hunter-gatherers with corresponding features of industrialised populations. We argue that mismatches in these domains are partially responsible for of a vast array of mental illnesses, ranging from common mood disorders to behavioural pathologies and psychotic spectrum disorders. We hope that this chapter stimulates the generation and testing of mismatch hypotheses and, eventually, trials of interventions based on mismatch reduction. We end by offering suggestions for methodological approaches to this future research.