Personality Disorders

Borderline- A mental illness with repetitive and unstable moods (disorder of emotion regulation), interpersonal relationships, self-image, and behavior. It disrupts one's life and sense of self-identity.
http://www.nimh.nih.gov/health/publications/borderline-personality-disorder-fact-sheet/index.shtml

Schizotypal- A mental illness that the person has few if any relationships with anyone. They compose an introverted interaction keeping them from interacting with anyone and in turn have dilemmas with anxiety when facing social situations.
http://www.mayoclinic.com/health/schizotypal-personality-disorder/DS00830

Paranoid- A mental illness that the person sees everyone displayed as mistrustful and suspicious. The illness is diagnosed when the patient is thoroughly distressed, disabling, or the emotions persistent.
http://www.mentalhealth.com/dis/p20-pe01.html

Narcissistic- A mental disorder that the person has a high opinion of themself and craves for the same admiration they offer themselves. They believe themselves to be superior to others and have complete disregard for the others feelings. Said though that they are really fragile when critized.

http://www.mayoclinic.com/health/narcissistic-personality-disorder/DS00652

Histrionic- A mental illness that the person has very unstable emotions and a distorted self-impression. They rely on the opinion of others to boost their confidence and feel they are not worthy of a good opinion upon themselves. They go through extreme measures to direct attention to themselves, making it "dramatical".

http://my.clevelandclinic.org/disorders/personality_disorders/hic_histrionic_personality_disorder.aspx

Antisocial- A chronic mental illness that the person's ways of thinking, perceiving situations, and relating to others is dysfunctional. The illness doesn't give regard for what is right or wrong. Also known as sociopathic personality disorder and sometimes seen as psychopathy.

http://www.mayoclinic.com/health/antisocial-personality-disorder/DS00829

Obsessive-Compulsive- A condition in where a person extremely preoccupies themself with rules, orderliness, and control

http://www.nlm.nih.gov/medlineplus/ency/article/000942.htm

Avoidant- A mental illness that has the person avoiding any contact or situation in which they might find themselves anxious or embarassed. The constant worry that they will be ridiculed, criticizied, or rejected puts them on constant alert of suffering anxiety attacks, developing a a wall around themself of self-protection.

http://www.social-anxiety-shyness-info.com/art/sad/a-11-avoidant-personality.htm

Racism

Many traits inflict upon the behavior of a person to be racist. In general though it's due to your education, not school-wise but how you were raised, by what kinds of people, where you were raised and how everyone around you treated each other in that place, and more. Or it could be minimal things like religion, gender, hair colors, etc. When we find a "fault", or different feature, that sets them apart from one person they believe  that they are better.
There is also a slight problem with dominative people. They feel superior and it makes them want to be at the top, thus shunning the ones that might fall lower in their perspective. Racism is mostly scene towards those with different skin colours because it is what stands out most. Another example is a very prosperous person that feels disgust upon seeing a rather poor person beg for money on the streets with ragged clothing.
Sometimes, it's not only this, but also the jealous anger that can create racist actions. If we see someone from another race, or so, doing better than we, that might cause way for racism. Or if one person is better than the rest, he'll see himself as a better creation than the others.
An important reason is that humans may feel safe to the opposing race. For example the way a gazelle avoids a tiger because it is dangerous. We might take for example terrorists, We group them from where they come from and the innocent people there. We might take them in as dangerous people. It is for cause of fear that we inch away from any possible chance we might be in danger.

Importance of Psychology

I beleive psychology to be important because it helps us discover a lot about the way humans and animals work. It is a part of our everyday life and is important because without it, we'd be clueless upon why we react the way we do to simple or complicated things. Comprehension of one's self is an important step to moving on in life and being able to retain what you learned. It helps to mature and turn yourself into a reliable step for future progress.