"Beck (1983) distinguished between deprivation depression (caused by the loss of affiliative opportunities) and defeat depression (caused by failure to achieve desired goals). In Beck’s view, ‘sociotropic’ people, to whom affiliative needs are of particular importance, are more prone to develop ‘deprivation depression’ when their affiliative needs are frustrated, while ‘autonomous’ people, who are more self-reliant, are more prone to ‘defeat depression’, when their competitive needs are frustrated. A parallel distinction was made by Blatt (1974) between anaclitic depression (Greek, ana = upon; klino = lean), caused by failure to form lasting attachment bonds, and introjective depression, occurring in people with a strict, critical superego, who fail to live up to the high standards they demand of themselves. In addition, Birtchnell (1993) has distinguished between horizontal depressions, which result from dissatisfactions in interactions involving ‘closeness’ and ‘separateness’, and vertical depressions, which result from dissatisfactions in ‘upper-to-lower’ (rank) interactions."
"Whereas attachment theory proposes that depression is an adaptive response to losing an attachment figure and conceiving of oneself as unlovable, rank theory proposes that depression is an adaptive response to losing rank and conceiving of oneself as a loser. The adaptive function of the depression, according to rank theory, is to facilitate losing and to promote accommodation to the fact that one has lost. In other words, the depressive state evolved to promote the acceptance of the subordinate role and the loss of resources which can only be secured by holding higher rank in the dominance hierarchy. The function of this depressive adaptation is to prevent the loser in a status conflict from suffering further injury and to preserve the stability and competitive efficiency of the group by maintaining social homeostasis.
In circumstances of defeat and enforced subordination, an internal inhibitory process comes into operation which causes the individual to cease competing and reduce his level of aspiration (Gilbert, 1992). This inhibitory process is involuntary and results in the loss of energy, depressed mood, sleep disturbance, poor appetite, retarded movements, and loss of confidence which are the typical characteristics of depression.
The selective advantage of an evolved capacity for the recognition and acceptance of rank difference in social groups is that it reduces aggressiveness and establishes precedence in granting rights of access to indispensable resources such as territory, food, and potential mates. It follows that gaining rank is associated with elevated mood and losing rank with depressed mood."
"To be popular and hold rank within a group are immensely desirable accomplishments; to perceive oneself as unpopular and without rank are causes of misery and unhappiness; while to be rejected from the group altogether is one of life’s greatest disasters. It is in terms of these factors that joy and sorrow, mania and depression, contentment and anxiety can be most readily understood.
One important contribution of rank theory is that it has proposed a hypothesis of how depression actually evolved: it emerged as the yielding component of ritual agonistic conflict. This has been called the yielding subroutine (Price and Sloman, 1987). The adaptive function of the yielding subroutine is twofold: first, it ensures that the yielder truly yields and does not attempt to make a comeback, and, second, the yielder reassures the winner that yielding has truly taken place, so that the conflict ends, with no further damage to the yielder. Relative social harmony is then restored.
Similarly, we may offer the hypothesis that mania evolved as the winning component of ritual agonistic behaviour: the winning subroutine. Here again, the adaptive function is twofold: first, it ensures that the winner truly wins and makes clear that any attempt at a comeback by the yielder will be successfully resisted, and, second, it ensures that should the yielder attempt to reopen the conflict, the winner will have such resources of confidence, determination, strength, and energy that he will force the yielder to yield for good and all.
Both yielding and winning subroutines thus ensure that social change is accomplished relatively quickly without too much disruption of group activities and that once it has occurred it will prove lasting. The object of the losing strategy is damage limitation, that of the winning strategy is status preservation. Inevitably, such subroutines carry greater significance among group-living species than among those living a solitary existence."
"That the incidence of depression is higher and its course longer than hypomania suggests that natural selection has favoured the prolonged yielding subroutine over its winning equivalent. This could reflect the evident fact that in any asymmetrical society there are potentially more losers than winners. It also reflects the fact that few people are ever known to present themselves at psychiatric clinics complaining of ‘suffering’ from hypomania. Inevitably, the medical services are concerned with losers rather than winners, and whereas the loser in a physical encounter is more likely than the winner to end up in Casualty, so the loser in a ritual encounter is more likely than the winner to end up in the Psychiatric Out-Patients Department."