Brazil's affinity for nicknames might stem from the country's historically high illiteracy rate. As such, shortened spoken names are typically used more often than longer birth names. In Brazilian society, the use of a first name or nickname is a mark of intimacy. It's also often a class signifier.

Brazil's president, Luiz Inacio Lula da Silva, is known to all by his nickname, Lula. Clergymen, doctors, and other professionals are frequently known by an informal name. The phone book for the town of Claudio even lists inhabitants by their nicknames rather than their surnames.

Some scholars speculate that the use of single names could have its roots in the slave system. (Slavery was abolished in Brazil in the late 19th century.) When they were documented, slaves would be referred to either by their first name only—say, Joao—or by their first name and country of origin—say, Joao Congo.

When the English introduced soccer to Brazil in the 1800s, Brazilians referred to players in the English manner, by their surnames. But as the sport grew in popularity, nicknaming took over. When the Brazilian national team played its first match in 1914, the squad featured a forward called Formiga, which means "ant" in Portuguese. Players with the same first name often change their moniker to differentiate themselves. In recent decades, there have been several Ronaldos at the national level. One became known as Ronaldao, meaning "big Ronaldo." Another became Ronaldinho, meaning "little Ronaldo." When another Ronaldinho came along in the late 1990s, he was called Ronaldinho Gaucho—that is, "little Ronaldo from Rio Grande do Sul." Eventually, the first Ronaldo left the Brazilian national squad, so Ronaldinho became Ronaldo. Ronaldinho Gaucho became Ronaldinho.