High mobility explains demand sharing and enforced cooperation in egalitarian hunter-gatherers.

'Simple' hunter-gatherer populations adopt the social norm of 'demand sharing', an example of human hyper-cooperation whereby food brought into camps is claimed and divided by group members. Explaining how demand sharing evolved without punishment to free riders, who rarely hunt but receive resources from active hunters, has been a long-standing problem. Here we show through a simulation model that demand-sharing families that continuously move between camps in response to their energy income are able to survive in unpredictable environments typical of hunter-gatherers, while non-sharing families and sedentary families perish. Our model also predicts that non-producers (free riders, pre-adults and post-productive adults) can be sustained in relatively high numbers. As most of hominin pre-history evolved in hunter-gatherer settings, demand sharing may be an ancestral manifestation of hyper-cooperation and inequality aversion, allowing exploration of high-quality, hard-to-acquire resources, the evolution of fluid co-residence patterns and egalitarian resource distribution in the absence of punishment or warfare

Characterization of hunter-gatherer networks and implications for cumulative culture

Social networks in modern societies are highly structured, usually involving frequent contact with a small number of unrelated friends' 1. However, contact network structures in traditional small-scale societies, especially hunter-gatherers, are poorly characterized. We developed a portable wireless sensing technology (motes) to study within-camp proximity networks among Agta and BaYaka hunter-gatherers in fine detail. We show that hunter-gatherer social networks exhibit signs of increased efficiency 2 for potential information exchange. Increased network efficiency is achieved through investment in a few strong links among non-kin friends' connecting unrelated families. We show that interactions with non-kin appear in childhood, creating opportunities for collaboration and cultural exchange beyond family at early ages. We also show that strong friendships are more important than family ties in predicting levels of shared knowledge among individuals. We hypothesize that efficient transmission of cumulative culture 3-6 may have shaped human social networks and contributed to our tendency to extend networks beyond kin and form strong non-kin ties

A Turbulent political history and the legacy of state Socialism in the Baltic countries

This chapter provides a survey of the political, socio-economic and demographic development of the Baltic countries. It is meant to give readers a general understanding of the setting in which large urban housing estates were built from the 1960s to the 1980s. The chapter begins with an account of the history of the Baltic countries, including their emergence as independent nations, their incorporation into the USSR and their reappearance on the world map in 1991. The second section analyses the modernisation of the Baltic economies, the Soviet strategies for industrialisation and their impact on the housing sector. The Baltic region enjoyed somewhat higher living standards and exhibited greater openness to Western influences than other union republics, which made Estonia, Latvia and Lithuania attractive to economic migrants from other parts of the USSR. The analysis also shows that the Baltic countries experienced demographic modernisation earlier than other regions of the USSR. A high demand for labour is driven by Soviet strategies for economic development, and slow population growth in the host countries, particularly in Estonia and Latvia, contributed to the persistence of high levels of immigration throughout the post-war decades. Due to their large numbers, migrant workers significantly transformed the composition of the urban population in the Baltic countries. Through a combination of factors, including the housing allocation mechanism, immigrants gained privileged access to new accommodation, and they became over-represented in the housing estates. This development connects the future of the housing estates with the integration of immigrants who settled in the region during the Soviet era