You can't describe people without having at least a piece of knowledge of history, culture and common values can help you in the process of getting to know people.
Ethnically speaking Costa Rica has an homogenous population, 97% of people is mestizo (Mixed blood, spanish with natives) or european descent. Afro-caribbean people represents 3% of total population. They have arrived of the new world in the 1870's, hired from caribbean islands in order to help costa ricans to build railroad from San Jose to Limon.
Also there are several indigenous tribs. Six natives languages has survived the time. Cabecares and bribris (biggest indigenous tribs) are south east of the country. Sice 1977 indigenous tribs acquire rights to land reserves and create programs to preserve native culture in the country. Following goverments, and acting by these initiatives, gives indigenous tribes the right to vote on 1994.
Children are exposed to the "rights" that they have as citizens in the public school system. The National Anthem includes the line, "let work and peace always live." In 1987 the country's president, Oscar Arias, won the Nobel Peace Prize for his work on Esquipulas II, a plan to bring peace to Central America.
A third aspect of Costa Rica is simply the hospitality of its people. Despite a growth in crime and drug problems, on average, the country is a remarkably friendly environment. In the countryside there is always a warm pot of coffee on the wood stove, ready to be served to the unexpected visitor. The people are polite, curious, and inclined to smile. The tourism of the last decade has brought with it an assortment of con-artists, hustlers, and entrepreneurs, but nonetheless almost all travelers are made to feel welcome.
Of course one cannot describe the people of a nation without mentioning their religion. Costa Rica is a Catholic land, like most of Latin America. A host of evangelical churches emerged in the 1970's and have become well established, but nearly 80% of the population remains Catholic. However, only about 20% of the Catholics attend mass regularly. Holy Week is the time of year when there is the most pronounced expression of the faith and the nation comes to a standstill during this holiday.