Here, the statement of fact is that people are attracted to similar others. Schizophrenia is genetic. Here, again, you want to make the statement of fact that schizophrenia is genetically caused. Notice two things. At most, the research suggests that your genetic makeup can enhance the likelihood that you will develop schizophrenia.
Environment is also important.
Here, the statement of fact refers to what people believe. 3-part division of personality into the id, the ego, and the superego. People have a need to avoid feeling responsible for producing aversive consequences. Sometimes, you will wish to cite a source that you did not actually consult, but which is mentioned in something you did consult. First of all, you should try to get the original source.