The first passage was referring to the ability of immigrants to completely start over in a new place. Immigrants have to forget everything they've been taught, and learn a different culture. They have to adapt to a foreign way of life, and figure out what is acceptable or unacceptable. I admire people who are willing to relearn everything for a chance at a better life for themselves and their families. I would probably never have that courage, and I look up to the people who do.
Passage two says Americans enjoy freedoms that are sometimes unavailable in other countries. Americans also work with what they enjoy, and are sometimes selfish, ensuring their success. This passage gives me a more negative view, although being selfish can be good. It ensures your survival and can get you much farther than being generous usually does.
In the next passage, the speaker is stating true Americans shouldn't consider themselves a mix of American and the country of their birth. He believes that once you arrive in America and gain citizenship, your full loyalty should be directed to America. Once your arrive in America, you're supposed to give up all loyalty to the country you left; it shouldn't be spilt between both countries. I agree to a certain extent. Once you arrive here, you're giving up on your country. If you immigrate here, it's because you believe America has more to offer than wherever you were before. In return for the opportunities, you should feel some loyalty for America. However, I also believe it is important to keep parts of your culture with you. Your culture sets you apart from everyone else, and learning from each others' cultures can teach a lot of respect and tolerance.
Passage four is arguing most Americans are risk-takers, or hypo-manic. Immigrants are the ones more likely to take chances, risking everything for the possible gain. I agree that immigrants are more daring than the people who stay behind. However, not all Americans possess this quality; some children who are cautious may be too young to decide for themselves, and others may not inherit the quality from their parents.
The last passage is supporting the idea of "American DNA." Some people believe it's what distinguishes Americans from other cultures. The gene, a risk-taking gene, is thought to be the reason immigrants immigrate. The majority of Americans possess this gene, immigrants and children of immigrants. I think the gene causing risk-taking contributes to the reasons of immigrants, but isn't the only deciding factor. Many other events can contribute as well.