Social rank theory

1. Social rank theory is the biological explanation of clinical depression, and it works through evolution.
2. It was put forward by Stevens and Price, who argued that human beings evolved to live in groups arranged in a hierarchy.
3. Inside such a group people compete for rank, status and the resources that come with them.
4. The trigger the theory focuses on is losing rank and then being unable to regain it.
5. Depression is treated as an adaptive response to that loss, and the appeal to evolution is what makes the explanation a biological one.

The evolutionary function of depression

1. In our evolutionary past, competing for rank was dangerous, because a losing fight risked injury or being pushed out of the group.
2. Low mood, loss of energy and loss of motivation make the loser stop competing and lower their ambitions, which keeps them out of a fight they cannot win.
3. Anything that improved survival in that way would be passed on to later generations, so the theory treats depression as an inherited adaptation rather than a fault in the person.

How a lower rank reduces conflict

1. The theory says depression makes a person accept a subordinate role instead of fighting on.
2. Outward symptoms such as sadness, crying and withdrawal act as a signal to everyone else that the person is not fit to compete.
3. That signal discourages others from attacking again, because there is no longer anything to win.
4. It also reassures the winner that the contest is over, so the winner has no reason to press the advantage.
5. A damaging, drawn-out struggle is avoided, so the theory argues the individual and the group both benefit.
6. Yielding in this way is how a lower rank reduces conflict.
7. Tandoc et al. (2015) found that Facebook envy predicted symptoms of depression, and envy on Facebook is a sense of being lower in rank.
   1. That study is correlational, so it supports the theory without showing that a lower rank causes depression.

Criticisms and the reductionism debate

1. The debate this theory runs into is reductionism and holism.
2. Being reductionist has an upside, because one clear mechanism is easier to test than a long list of interacting causes.
3. Social rank theory is reductionist, because it explains a complex disorder through a single evolutionary mechanism.
4. A holistic view says depression has many interacting causes, including life events, relationships, money worries and the way a person thinks.
5. The evolutionary claim is hard to test, since nobody can observe how depression worked for our distant ancestors.
6. It also struggles to explain why depression can be so disabling and last so long, if its function is to protect the person.
7. It says little about why some people who lose rank become depressed and others do not.

Turning this into marks

1. When two parts of the theory are asked for, make them genuinely separate: the evolutionary function of depression, and the way a lower rank reduces conflict.
2. Name Stevens and Price and the loss of rank, because a general reference to stress or low mood does not secure the knowledge mark.
3. Where a question asks for criticisms, use the reductionism and holism debate and the difficulty of testing an evolutionary claim.
4. The mark most often lost is giving the ABC model when the question asked for the biological explanation of depression.