How institutions shaped the last major evolutionary transition to large-scale human societies.

What drove the transition from small-scale human societies centred on kinship and personal exchange, to large-scale societies comprising cooperation and division of labour among untold numbers of unrelated individuals? We propose that the unique human capacity to negotiate institutional rules that coordinate social actions was a key driver of this transition. By creating institutions, humans have been able to move from the default ‘Hobbesian’ rules of the ‘game of life’, determined by physical/environmental constraints, into self-created rules of social organization where cooperation can be individually advantageous even in large groups of unrelated individuals. Examples include rules of food sharing in hunter–gatherers, rules for the usage of irrigation systems in agriculturalists, property rights and systems for sharing reputation between mediaeval traders. Successful institutions create rules of interaction that are self-enforcing, providing direct benefits both to individuals that follow them, and to individuals that sanction rule breakers. Forming institutions requires shared intentionality, language and other cognitive abilities largely absent in other primates. We explain how cooperative breeding likely selected for these abilities early in the Homo lineage. This allowed anatomically modern humans to create institutions that transformed the self-reliance of our primate ancestors into the division of labour of large-scale human social organization.

An evolutionary model explaining the Neolithic transition from egalitarianism to leadership and despotism.

The Neolithic was marked by a transition from small and relatively egalitarian groups, to much larger groups with increased stratification. But the dynamics of this remain poorly understood. It is hard to see how despotism can arise without coercion, yet coercion could not easily have occurred in an egalitarian setting. Using a quanti- tative model of evolution in a patch-structured population, we demonstrate that the interaction between demographic and ecological factors can overcome this conundrum. We model the co-evolution of individual preferences for hierarchy alongside the degree of despotism of leaders, and the dispersal preferences of followers. We show that voluntary leadership without coercion can evolve in small groups, when leaders help to solve coordination problems related to resource production. An example is coordinating construction of an irrigation system. Our model predicts that the transition to larger despotic groups will then occur when: 1. surplus resources lead to demographic expansion of groups, removing the viability of an acephalous niche in the same area and so locking individuals into hierarchy; 2. high dispersal costs limit followers' ability to escape a despot. Empirical evidence suggests that these conditions were likely met for the first time during the subsistence intensification of the Neolithic.

Intensive care survivors’ experiences of ward-based care: Meleis’ theory of nursing transitions and role development among critical care outreach services.

Aims and objectives. To explore the psychosocial needs of patients discharged from intensive care, the extent to which they are captured using existing theory on transitions in care and the potential role development of critical care outreach, follow-up and liaison services. Background. Intensive care patients are at an increased risk of adverse events, deterioration or death following ward transfer. Nurse-led critical care outreach, follow-up or liaison services have been adopted internationally to prevent these potentially avoidable sequelae. The need to provide patients with psychosocial support during the transition to ward-based care has also been identified, but the evidence base for role development is currently limited. Design and methods. Twenty participants were invited to discuss their experiences of ward-based care as part of a broader study on recovery following prolonged critical illness. Psychosocial distress was a prominent feature of their accounts, prompting secondary data analysis using Meleis et al.’s mid-range theory on experiencing transitions. Results. Participants described a sense of disconnection in relation to profound debilitation and dependency and were often distressed by a perceived lack of understanding, indifference or insensitivity among ward staff to their basic care needs. Negotiating the transition between dependence and independence was identified as a significant source of distress following ward transfer. Participants varied in the extent to which they were able to express their needs and negotiate recovery within professionally mediated boundaries. Conclusion. These data provide new insights into the putative origins of the psychosocial distress that patients experience following ward transfer. Relevance to clinical practice. Meleis et al.’s work has resonance in terms of explicating intensive care patients’ experiences of psychosocial distress throughout the transition to general ward–based care, such that the future role development of critical care outreach, follow-up and liaison services may be more theoretically informed.