Second , we show that network composition , individual network central ity , and network structure are associated with important health behaviors and health and development outcomes in different context s across multiple levels of analysis and across distinct network types .
Lastly , we highlight the opportunities for health research ers and practitioners in LMICs to 1 ) design effective studies and interventions in LMICs that account for the sociocentric network positions of certain individuals and overall network structure , 2 ) measure the spread of outcomes or intervention externalities , and 3 ) enhance the effectiveness and efficiency of aid based on knowledge of social structure .
In low- and middle-income countries ( LMICs ) , naturally occurring social networks may be particularly vital to health outcomes as extended webs of social ties often are the principal source of various re sources .
Dynamic social networks promote cooperation in experiments with humans
Human population s are both highly cooperative and highly organized . Human interactions are not r and om but rather are structured in social networks . Importantly , ties in these networks often are dynamic , changing in response to the behavior of one 's social partners . This dynamic structure permits an important form of conditional action that has been explored theoretically but has received little empirical attention : People can respond to the cooperation and defection of those around them by making or breaking network links . Here , we present experimental evidence of the power of using strategic link formation and dissolution , and the network modification it entails , to stabilize cooperation in sizable groups . Our experiments explore large-scale cooperation , where subjects ’ cooperative actions are equally beneficial to all those with whom they interact . Consistent with previous research , we find that cooperation decays over time when social networks are shuffled r and omly every round or are fixed across all rounds . We also find that , when networks are dynamic but are up date d only infrequently , cooperation again fails . However , when subjects can up date their network connections frequently , we see a qualitatively different outcome : Cooperation is maintained at a high level through network rewiring . Subjects preferentially break links with defectors and form new links with cooperators , creating an incentive to cooperate and leading to substantial changes in network structure . Our experiments confirm the predictions of a set of evolutionary game theoretic models and demonstrate the important role that dynamic social networks can play in supporting large-scale human cooperation
Second , we show that network composition , individual network central ity , and network structure are associated with important health behaviors and health and development outcomes in different context s across multiple levels of analysis and across distinct network types .
Lastly , we highlight the opportunities for health research ers and practitioners in LMICs to 1 ) design effective studies and interventions in LMICs that account for the sociocentric network positions of certain individuals and overall network structure , 2 ) measure the spread of outcomes or intervention externalities , and 3 ) enhance the effectiveness and efficiency of aid based on knowledge of social structure .
In low- and middle-income countries ( LMICs ) , naturally occurring social networks may be particularly vital to health outcomes as extended webs of social ties often are the principal source of various re sources .