From here onwards is the most important part from the viewpoint of economics of characters. That is to say, characters are in a sense in a world where there are no correct answers, and it is not that they will sell if you design them according to an equation. It is essential to know how the human brain works to understand this kind of phenomenon. It is necessary to study how human beings deal with uncertainty in which they do not know what is going to happen. The field of behavioral economics has studied this. This field became generally known after Daniel Kahneman was awarded the Nobel Prize for Economics. In a word, what he did was to study how human beings judge and behave in uncertain conditions. To mention the conclusion first, the research result was that they deviate from the optimal behavior expected from classical economic theory. For example, the correct answer to the question of the optimal investment strategy in the case of lottery tickets is not to buy them, but every one buys them. The fact that human beings do not behave according to economic rationality is best understood if we take the case of gambling. This is true in all kinds of cases apart from gambling.

 Economics will not be necessary if it cannot explain human behavior, so this is a tremendous challenge for economists as it questions the meaning of their existence. This challenge has been taken up by behavioral economics. Dopamine, which I mentioned above, is secreted inside the brain when someone is happy, so this becomes the currency of remuneration. Neural economics is emerging as a new field by combining theories with the workings of dopamine as the currency of remuneration. For example, what would a consumer buy in a convenience store? Does he/she buy something because a character is attached, does he/she buy something according to his/her mood, rather than following some kind of rule? In order to investigate this to the end, we would have to think about the workings of the system of remuneration inside the brain. To put it simply, human brain evolves or learns to maximize the amount of dopamine secreted. But the happiness and timing for dopamine to be secreted differs considerably from person to person. For example, for a mathematician, thinking about a difficult and unsolvable problem for ten to twenty years leads to the secretion of dopamine more than anything else. A mathematician wakes up every morning very happily thinking that he/she can think of that unsolvable problem again today. Therefore, this is a kind of culture inside the brain, and investigating how this culture is constructed leads to solving an extremely difficult equation. The main issue with characters seems to involve happiness that leads to secretion of dopamine and evolution of the brain.

 An epoch-making study in this field was reported by a group from Cambridge University in 2003. They discovered that uncertainty increases happiness for the brain through the activity of dopamine. We know by experimental results that more dopamine is secreted over a longer time when food is given to a monkey who is hopeful and anxious in a condition of uncertainty. In other words, the brain likes uncertainty. That is why people gamble. There is a very interesting story behind why the structure of the brain is like that, starting from monkeys. There is something called reinforcement learning in learning theory. This differs from learning in which there is a teacher who tells you the correct answer. To put it simply, in reinforcement learning, when it is found that dopamine is secreted inside the brain as a result of a particular action, they reinforce the action at a higher level that originally became the cause of dopamine secretion. For example, since in the case of mathematicians dopamine is secreted when they think of a problem, they reinforce the practice of thinking about a higher-level problem related to it.

 Generally speaking, dopamine is secreted when someone goes to a maid café. It is necessary to establish a brain culture in which how to reinforce this circuit is the responsibility of each individual. The most important issue in reinforcement learning is how to strike a balance between using a source of remuneration that is certain to always cause pleasure if employed, and search for an unknown higher-level source of remuneration. This is also a very difficult theoretical problem, since if a creature always does what it knows would definitely give it pleasure, it would peter out. On the other hand, if it keeps taking high risks by searching for unknown source of remuneration, it would find it dull as there will be fewer chances of remuneration. It is very important to get a balance between these two. This still remains an unsolved problem in reinforcement learning. Schultz's experiment mentioned above presents a very important clue in thinking about this problem. That is to say, if a tendency to prefer uncertain situations or things to a certain extent is inserted into the system of remuneration of the brain, the brain will search for it to a certain extent. So it is gradually being discovered that such systems are built inside the brain.

 A British psychologist Bowlby discussed this problem from another perspective, and studied the common factors of children who cause problems when they became teenagers. As a result, he reached a hypothesis that for children it is very important to have a protector who provides them a safe haven during childhood, and children who do not have such a protector have a high probability of becoming delinquents later on. A safe haven here does not mean over protection. When a child investigates freely, the safe haven becomes a precondition for such investigations. Children can make investigations freely when they have someone who will warn them when something dangerous might happen, or who will sort things out later if something happens, for example. Bowlby refers to the emotion that children have towards such protectors as 'attachment', and concludes that the most important developmental task in stages of children's development is to have attachment towards something, and children who fail in this task have a high probability of delinquency. That is to say, the safe haven is for providing protection for free investigation. Bowlby's theory is very relevant when seen in the light of today's system of remuneration and reinforcement learning mechanism of the emotional system. For example, it can be used as a model that also applies to organizations. To have attachment to an organization does not mean being protected by the organization but is a precondition for one to freely investigate using the organization as a safe haven. I think it is a wonderful theory, and these things are consistent with the recent studies of emotional systems in brain science.

 I said that the archive of memory is important for creativity. The archive of memory is a safe haven for investigation. That is to say, improvising a performance freely on the piano is possible because there is a safe haven inside the brain of a certain amount of piano skills. A manga artist draws manga freely because he/she can draw lines properly. The issue of safe haven and the archive of memory related to it are very important, and herein lies the significance of keeping characters properly as an archive in the case of creating characters. Issey Miyake's office preserves all the original clothes that he has designed since his debut in the Paris Collection. When I asked Fujiwara Dai, who creates the brand A-POC, whether these would not get in the way when creating something new, he said that he could create comfortably because there is an archive which Miyake has created in the past. I think this probably fits the logic of the safe haven in the working of the brain. That is to say, those who do not know the past cannot create.

 In the end, as I have mentioned above, brain science suggests that emotions are adaptations to uncertainty and one of the very important conclusions is that emotions vary greatly according to individuals. In adaptation to cases which have definite correct answers, strategies would converge and individual differences would be small, but strategies for uncertain situations have all kinds of answers and we do not know which one is correct until afterwards. Thus emotional systems have allowed individuals to take different strategies. Different people have taken different strategies in the process of evolution. One person who takes a particular strategy might die because of this, but if another person survives, it is good for the species. Therefore, the fact that emotions have a wide range of individual differences is theorized from the viewpoint of adaptation to uncertainty.

 In brain science today, it is thought that creativity is in fact an extension of emotion being an adaptation to uncertainty. As in the case of 'feeling of knowing' mentioned above, the brain system, including memory, has developed to overcome uncertainty, and creativity is a by-product of this. For example, in a situation which involves adaptation to new conditions as the occasion demands, there is probably a connection between emotion, uncertainty, memory and creativity. This is an argument not about character creativity but an argument related to general matters. Before I go on to the discussion on the body, if you have any questions about the section on emotions, please ask them now.