"For a century, the human response to stress and danger has been defined as "fight or flight." A 2000 UCLA study by several psychologists noted that this research was based largely on studies of male rats and male human beings. But studying women led them to a third, often deployed option: gather for solidarity, support, advice. They noted that "behaviorally, females' responses are more marked by a pattern of 'tend-and-befriend.' Tending involves nurturant activities designed to protect the self and offspring that promote safety and reduce distress; befriending is the creation and maintenance of social networks that may aid in this process."