It’s easy to dismiss two recent incidents of apparent racism in Maine as aberrations, perhaps perpetrated by disturbed people. But dismissing them is akin to ignoring a problem and hoping for the best.

In late November a Brewer man, according to staff at the Togus Veterans Affairs hospital in Augusta, pledged to shoot and kill those of African descent in the Bangor area. That threat resulted in the local chapter of the NAACP considering canceling its annual Kwanzaa celebration. And earlier this fall, a teen of Somali descent reported that a white man threw sand or some other substance in his face while he ran in a cross-country competition. That incident is still being investigated.

The black population of Maine has nearly doubled over the past five years, according to the U.S. Census Bureau, but those of African descent still make up just 1 percent of the state’s population, making Maine the “whitest” state in the country. Does the lack of ethnic diversity contribute to racism, perhaps making those unfamiliar with people of different heritages more likely to accept stereotypes? Possibly. Regardless of the reason, racial hatred was not killed and buried in the 20th century, though many hoped it would be. Because it feeds on a natural wariness, distrust, fear and animosity toward those who do not look, talk and think as we do, it is destined to return.

None of us is ever truly free of prejudice, just as none of us is completely honest or completely selfless. These qualities are ideals, and advances toward those ideals are achieved in degrees. It is important to understand racism in this context. For proof that tolerance is a work in progress, take a look at the way blacks were portrayed in movies during the 1930s and 1940s. Or consider the jokes about gays that were prevalent in TV shows of the 1980s and 1990s. Watching these should make us cringe. But what are we doing now that will elicit a cringe 20 years down the road?

Beginning today, the Bangor Daily News is publishing a series chronicling Bangor’s ethnic past, with help from the Bangor Museum and Center for History. One story notes that in 1910, more than 17 percent of the city’s residents were foreign born, and another 23 percent were children of immigrants. Predictably, there were suspicions about the newcomers, with certain undesirable traits assigned to particular groups. But in the end, most of the immigrants were assimilated and accepted. But before Bangoreans pat themselves on the back, they should consider that acceptance may have come only when the Italian, French and Greeks could no longer be identified by their features, accents and clothes.

Until color blindness becomes a dominant genetic trait, blacks will struggle to overcome bias. Everyone else should struggle harder to see beyond pigmentation.