The Christmas bonus.

It is remuneration received by the employee, in addition to the usual twelve monthly installments. 

Origin.

The Romans called "strenae" exchanged gifts with friends to honor the gods, and as a sign of happy omen. A Roman tradition attributed the origin of the bonus king Titus Tatius, who was born in the habit of going (on January 1) to pick verbena, Strenua the sacred forest, the Force, or Strenia, the goddess of health, with in order to obtain divine protection during the new year. Another tradition supposed that the people went in procession to the palace to offer, while wishing him a good year, branches of the shrub verbena, considered as a bearer of happiness. The primitive simplicity disappeared, and bonuses came to be more or less luxurious objects, leading to degenerate into abuse.

The bonuses were very varied in nature. Arable bonuses correspond to the Golden Age; Then came the time when these were foods of all kinds; Later consisted of pieces of gold, silver and bronze; then furniture and clothing.

The bonuses were one of the rich expensive practice, ripped the poor, for the servants offered bonuses to their masters, citizens offered it to the princes, and the disciples to their teachers. The force of habit forced some to offer what they did not have. Against this obligation to give, wrote the Fathers of the Church, to prevent many Christians to forget what they were. Through these authors know about the custom of many people, especially the peasants, to put on the doors of their houses (during the night prior to January 1) tables laden with all kinds of food consumed for passersby.

In the Middle Ages, kings, princes and nobles continued to observe this practice.

The bonus as childish habit.

The bonus, in Spain, is also the gift of sweets that are distributed mainly in children's parties and Christmas day. 

It is customary among children, touring the neighborhood, house to house, singing carols accompanied by tambourines, friction drums and empty bottles of anis (like a musical instrument). In this case, instead of asking for money, children always ask for candies and sweets.