In this section, Chagnon explores the dynamics of Yanomami aggression. When trading and feasts fail to establish an alliance between neighboring villages, the situation will not remain peaceful for long. In cases without outright raiding, paranoia on both sides will often lead to suspicion and accusations of sorcery. This situation will eventually devolve into raiding, which Chagnon lists as the primary form of Yanomami warfare. Chest-pounding duels, while violent, are the opposite of raiding because they are proper duels and, as such, are subject to strict rules of conduct. Escalation from there, as seen in the described feast, includes side-slapping or hitting each other with the flat of a machete blade. The subsequent escalation is “club fights,” in which opponents attack one another with blunt objects like clubs or poles. These fights are more informal and severe and often arise from arguments over stealing food or women. During the fight, other men will usually join in as well. Because of such conflicts, many men have scars on the tops of their heads, and some men shave their heads to show off these scars. A larger village size leads to more club fighting, which presents a greater probability of the village fissioning.