In the process of human evolution, the biggest adaptive problems have been how to maintain a group and how to rise in rank in a group hierarchy. If an adaptive problem is solved, the probability the solver will survive and success in reproduction rises. Laugh and laughter is discussed in the frame that it has been used to solve the adaptive problem in this chapter. The trigger of laughter is the cognition of a discrepancy. The discrepancy is the difference between what is expected and the actual state. A discrepancy cannot be serious to cause laugh and laughter. If it is implicitly expected to be resolved, then it is likely to arise a laughter with positive feeling. When laughter is shared by some people, it functions to link them with friendly relationship. On the other hand, the laughter becomes derisive (ridicule) when the discrepancy is between a social norm and an actual behavior. The ridicule functions to one's supremacy over the target individual. This function has been adaptive in the society of dominance hierarchy.
TopAdaptive Problems Of Social Animals
Homo sapiens are primates, and thus have evolved as a social mammal. There are two kinds of benefits of grouping for adaptation. The first is that it becomes easier for animals to protect themselves, not only from predators, but also from other groups of the same species. For example, muskoxen are known for their clever defense against wolves or other predators. When they see predators, muskoxen run together for circle defensive formation so that they all try to face the threatening predators. Predators cannot attack them because of the risk to be injured by their big horn. Another example is that of chimpanzees making an extra effort to warn group members that seem ignorant of danger. The more the group members, the more likely they detect a predator. Generally, bigger groups have an advantage not only in defense against predators, but also in the conflict against human enemies. Out-group members are potential or actual rivals of a group, because they compete for the same resources in the hunter-gather society. Hence, smaller groups have been less likely to survive in the history of evolution.
The second benefit is that grouping makes it possible to do what an individual cannot do alone. For example, it is more beneficial and effective to hunt in a group than to hunt alone, as shown in the example of mammoth hunters. Furthermore, after the Cultural Big Bang about 50,000 years ago, the bigger the social groups, the more effectively cultural products, resulting from cultural and scientific innovations, are transmitted to each other. These are expected to cause social and scientific development. After coexisting with Homo sapiens, Neanderthals became extinct about 30,000 years ago in Europe. The reason for this was thought to be the intellectual inferiority of Neanderthals, but it is now believed to be because of their small group size (e.g., Shipman, 2015). The development of new hunting technologies among the Homo sapiens was enhanced through mutual interaction within their large social groups. This was of greater advantage for them to get resources in the Ice Age Europe. On the contrary, the Neanderthals’ lack of ability to develop such hunting technology led to their extinction.
However, the costs of maintaining a big group are high. The group has to maintain harmony so that the group members do not fight each other and the group is divided into a few smaller groups. Members have to understand each other in order to maintain their group. When a group consists of only two individuals, it is only one whom each member has to understand. When the group has three individuals, each member needs not only to understand the other two individuals, but also the relationship between the two, as this is important to keep the group together. In this way, the number of inferences increases exponentially with the number of group members.