Antihaitianismo , also called anti-Haitianism in some English sources, is prejudice or social discrimination against Haitians in the Dominican Republic. Antihaitianismo includes prejudice against, hatred of, or discrimination against Haitians due to their physical appearance, culture, lifestyle, and language.
Antihaitianismo includes prejudice against, hatred of, or discrimination against Haitians and their culture, lifestyle, language, not strictly their race.
Based on the color of their skin and their African heritage, Haitians, and more generally people of African descent, have been stigmatized in the Dominican Republic, as in other countries in the Western Hemisphere, since the arrival of enslaved Africans in the 16th century. This historical stigmatization manifests itself as an ideology called antihaitianismo (anti-Haitianism), whose origins can be linked to the racial prejudices of the Spanish inhabitants of the colony of Santo Domingo, as pointed out by Ernesto Sagás of Colorado State University. Spanish colonization in the 16th century brought sugar, slavery and also racial prejudice to the island. To be sure, it should be stated that there are many Dominicans who proudly identify with their African heritage and treat Dominicans of Haitian descent with respect. https://atlantablackstar.com/2015/03/18/8-ways-haitians-have-been-severely-mistreated-in-the-dominican-republic/
The African slaves in Haiti fought and famously won their freedom and independence. They were able to project their power into the Spanish part of the island, and Haiti took control of the Dominican Republic for a generation. Some say the elite in the Dominican Republic still feel stung by the insult of having had to answer to Haitians in that era. Relations between the countries through the early 1800s were long, complicated and bloody. But the key event was the long War of Independence fought by Dominicans against Haiti, which began in 1844. It's the longest war in the Republic's history.
In 1937, Dominican government forces launched a bloody campaign of ethnic cleansing against people of Haitian descent that left thousands, or perhaps even tens of thousands, dead. It became known as the perejil or "parsley" massacre. Supposedly, troops who'd found a suspected Haitian would hold up a sprig of parsley and ask them to name it. Those who could not pronounce its Spanish name — perejil — with a properly rolled "r" were presumed to be Haitian Creole speakers, not "true" Dominicans, and killed. https://www.vox.com/2015/6/18/8802587/dominican-republic-haitian-deportation