Humor can be used as a tool of social oppression. Groups can ridicule those members low in status. A subset of the group can also form a small group that ridicules people outside the in-group as Other. Humor can be employed as part of a propaganda campaign to dehumanize other groups, which may be a precursor to violence. Mulkay, in his book On Humour, argues that it is not the humor itself that is oppressive, because humor is fundamentally non-serious; rather, what can be oppressive are the serious ends to which the humor is employed. Be that as it may, there are many instances where the target of the humor is not joining in the laughter and might in fact be terrorized.
What I did mean to say is that, even in the most unoppressed, egalitarian, or emotionally harmonized group, there are natural differentiations of status that develop from the grassroots upward. Recent research on bee hives suggest that decisions are made by consensus, and within human groups, there may be more consensus used to confer status than it at first appears. On the other hand, even in the most apparently rigid vertical hierarchy, leaders are wise to satisfy important factions of a group politically and build coalitions. And within a group that has a formal hierarchy, the informal social power might be other than it appears. Members who are technically low status within the formal structure of the group may have outsized informal authority. Again, the point is not that all hierarchies are good, but that all groups, including harmonious groups with little or no oppression, have status differentiation.
Another point raised in the literature (Terrion and Ashforth, 2002) is that, within a group that strives for cohesion, the target of putdown humor is often a higher status member, a member whose status is not threatened by the teasing deprecation. Low respect is marked by an absence of putdown humor (70). So humor's disparaging quality does not have to be aggressive and alienating of its targets. Terrion and Ashforth conclude that highly cohesive groups may practice self-deprecation and ritual gentle putdowns, and that that practice signals to others in the group that each member subordinates his or her welfare to the welfare of the group (73).
The earlier sections of this series might have left the impression that I was arguing that all humor is put to benign purposes. The point of this section is to make clear that that is not the case. Humor can be part of oppression. The converse is also not the case: not all humor, even humor that clearly deprecates others, is necessarily oppressive. Both in its oppressive and non-oppressive instances, humor can adjust status within a group.
Terrion, Jenepher L. and Blake E. Ashforth. (2002). "From 'I' to 'We': The Role of Putdown Humor and Identity in the Development of a Temporary Group." Human Relations, 55 (1): 55-88.