Immune system aging, a process known as immunosenescence, involves a striking rearrangement affecting all immune cells, resulting in an increased rate of infections and a major incidence of autoimmune diseases and cancer. Nonetheless, differences in how individuals of the same chronological age carry out this immunosenescence establishment and thus the aging rate have been reported. In the context of neuroimmunoendocrine communication and its role in the response to stress situations, growing evidence suggests that social environments profoundly influence all physiological responses, especially those linked to immunity. Accordingly, negative contexts (loneliness in humans/social isolation in rodents) were associated with immune impairments and decreased lifespan. However, positive social environments have been correlated with adequate immunity and increased lifespan. Therefore, the social context in which an individual lives is proposed as a decisive modulator of the immunosenescence process and, consequently, of the rate of aging. In this review, the most important findings regarding how different social environments (negative and positive) modulate immunosenescence and therefore the aging rate, as well as the role of stress responses, hormesis, and resilience in these environments will be explained. Finally, several possible molecular mechanisms underlying the effects of negative and positive environments on immunosenescence will be suggested.

In the Neolithic megasite at Çatalhöyük families lived side by side in conjoined dwellings, like a pueblo. It can be assumed that people were always in and out of each others' houses – in this case via the roof. Social mechanisms were needed to make all this run smoothly, and in a tour-de-force of botanical, faunal and spatial analysis the authors show how it worked. Families stored their own produce of grain, fruit, nuts and condiments in special bins deep inside the house, but displayed the heads and horns of aurochs near the entrance. While the latter had a religious overtone they also remembered feasts, episodes of sharing that mitigated the provocations of a full larder.