The Rationality of Oaths in Armed Struggle: A Dynamic Model of Commitment and the Mau Mau Insurgency (1952–1956)

In this paper, we develop the rationality of oath giving and the socially functional role that oaths can play in securing the commitment of members of conflict groups. Oaths are a reoccurring feature of insurgencies, armed struggles, and revolutionary movements. Oaths grow out of a general set of cultural practices that leverage superstitious beliefs to perform socially valuable functions and to produce normative conformity within groups. Applied to insurgencies, we argue that swearing oaths can motivate and sustain commitment to a cause. We apply our theory to the case of the Mau Mau rebellion in which oaths played a conspicuous role. Originally carrying religious meaning among Kenyan tribes, Mau Mau leaders repurpose oathings to enhance commitment. In its repurposed form, oathing incentives relied less on supernatural sanctions and more on credibly threatening defectors with physical in-group and out-group punishment. The Mau Mau highlights how an old cultural form can be used to ground innovations and how superstition-based practices that confer group benefits might continue to do so by permitting the creation of worldly incentives even after (or when) the superstition is stripped from them.