As it's already been pointed out IQ is a difficult area to look at as IQ is judged based on a particular standard which is a general breaking down of intelligence. You have a high IQ if you are exceptional in pretty much everything that you are tested against and if you drop in one area then your IQ as a whole goes down. This isn't how you can correctly measure intelligence as it neglects people who are intelligent in particular things but dumb to others.
But that's detracting so lets get back on topic.
From a Sociological perspective we are taught that views and opinions are motivated by a number of factors in society some you are aware of and others you may not so much be aware of. These are broken down into two areas, Primary Socialization and Secondary Socialization although many other people will refer to this as "Nurture versus Nature."
Primary Socialization is anything relating to your Family. This means your beliefs about something, Ethnicity, Social Class, Lifestyle, are all inherited as you grow up from your parents and family members. If you live in a family where your mother and father have strong views regarding Blacks, Asians etc. You will naturally have them too.
Secondary Socialization is where your "Media is evil" rants come into play. This is where your attitudes and beliefs are created by your reaction to society and institutions within it. If you read a particular newspaper you will conform to the views expressed in it.
So how does this all fit in with whether a person is a racist or not? Well this means that "IQ" plays less of a role in the topic as your beliefs are not created by how smart or dumb you are but rather how you are led to view the world. You can be smart and still be a racist, God we call Winston Churchill brilliant and look behind the scenes at how he viewed everyone in the British Empire who wasn't White, on the other hand we have people with low "IQ" who will treat everyone as an equal.
But we also reach an interesting point of where individuality comes into play. We all have the ability to believe whatever we want, along with picking and choosing things that suit of interests.
Human beings are each unique and we can't understand Human beings by generalising them as individuality prevents us from doing, so which brings the conclusion that regardless of Scientific, Sociological or Psychological understanding we will never really be able to understand Human beings.