Delight is an urge to display one's success.
Delight is an emotion that branches out from hope depending on the situation. Delight occurs when a pleasant situation predicted by hope is realized.
You feel delight when your prediction comes true. Delight occurs when an imaginary world in the brain corresponds with real world. People are delighted when they achieve a goal.
Players exchanging blows with each other when a batter hits a game-winning home run in baseball, a celebratory beer shower when winning the pennant race, a player's expression when scoring a goal in soccer, jumping for joy when you find out you passed an exam, raising a fist in triumph or cheering and so on― these are actions of delight. The person's whole body tenses up and they are extremely excited. People express delight with overflowing physical and mental energy. We can say that happy dances are quite literally the extreme expression of delight.
There is no delight which is not predicted. No matter how profitable a realization is, if it has not been thought of before it cannot bring delight. People will not feel delight unless they are aware that it is a result of their capability because delight is a display of self-competence. However, people think of many kinds of things, so there are very few things which have not been imagined. Even if people have never thought about a thing itself, they have thought about its results, so feeling delight is common.
For example, when you find a case on the road with 100, 000, 000 yen inside, you would feel just bewilderment at that time, not delight. However, you would feel delight if after returning the case you are rewarded and it makes you rich.
Extreme delight may make people cry. A delightful situation is recognized in the sensory association cortex, signals are sent to the motor association cortex, and we try to do something. If the delight is too strong, there no activities to digest it at the time, then we cry out of delight.
Well, why do we express delight like this? On reflection this is strange reaction, but it can also be explained by evolution.
Actions of delight are to show success to their fellows. This asserts that they are capable and requests their status in the society be raised. It is thought that people showed off when they successfully caught something when hunting, and gained respect from others in the primitive ages.
We can assume that this is the reason that victory poses are more prominent in men. When we imagine an athlete posing triumphantly it will most likely be a male athlete. This is not a coincidence.
In Japan, which treasures harmony, there is a tendency for delight to be hidden. Sumo, shogi, and go players would never express delight. This is because Japanese people don't like to push others aside.
Delight makes people continue and repeat their current action because it is pleasant. Therefore, delight can strengthen the effort put in to achieve a hope.
Also, the delight of a person who is recognized as on your side can become your delight because humans have the ability to sympathize. The delight of your loved one becomes your delight. In an addition, this positive emotion spreads around and enhances social relationships. Sharing delight with everyone produces unity.
Delight is a young emotion in the history of evolution. Delight exists only in animals which form groups because delight makes one appealing to those around. Delight also requires intellect because it needs prediction, so only humans and apes seem to feel it.
For example, chimpanzees cry like a lunatic when they find fruit. This is thought to be the delight of finding.