Many thanks for this important discussion.
I see social networks and relations as an evolving agenda. The quality of social networks is the major determinant of whether they ever help in ensuring food security: in the primitive era when work was group/community oriented, these support systems were reliant.
Also the quality of these support systems tends to also be location specific. It has been observed that the rural environment facilitates quality family life which, in turn, promotes a quality community and society (Refer to Buttel, F.H., & Flinn, W.L. Sources and consequences of agrarian values in American society. Rural Sociology, 1975,40, 134-151) and (Miller, M.K., & Crader, K.W. Rural-urban differences in two dimensions of community satisfaction. Rural Sociology, 1979, 44, Fall, 489-504).
Of course within rural and urban communities there are also marked differences in terms of the quality of social networks.
In conclusion, social support systems are critical in food security but their quality is an important factor. The extent to which one invest in them detemines the extent to which one can harvest from them. In Zimbabwe, it's often said 'kandiro kanoenda kunobva kamwe'
loosely translated to say 'when you give, you also get'