Nature vs. Nuture

  Hello everybody!
  It's surreal to think that we're already at the end of the first month of the year. I actually just celebrated another year since my birth a few days ago; it was like any other day, though. In all honesty, I don't feel any different. Odd, maybe? 
  But on to today's subject matter: psychology.
  I am currently enrolled in a psychology course, and I absolutely love it. I think it may be because it talks about the way we think, why we think that way, and what that way of thinking means. All of these ideas are things that I'm usually interested with, because I'm constantly thinking about the bridge between people's thoughts and their actions.
  Often, we run into a common debate in our discussions: Nature vs. Nurture. This argument is basically based on two conflicting ideas: one that say different actions and behaviors are born embedded in us, while the other say that these things are learned.
  It's really interesting, once you start thinking about it. We all know that the phenomenon in which a bird cares for her young would fall into the 'Nature' category, because no other bird teaches her how to do it. But it becomes a much more complicated distinction when applying it to humans, which are much more complex creatures.
  One good example is personality. Does she have a bad temper because it was passed down in her genes, or is it because she developed it from watching her dad blow up over nominal things on a routine basis? Is the reason why he is so pompous because of over-confidence being passed down in his mother's family, or is it because he just mimicked his mother's behavior? I for one have noticed that I love talking on the phone, as does my mother; is it because it is a genetic thing, or because of all those years seeing her with a telephone glued to her ear?
  Intelligence is also another thing that challenges the Nature vs. Nurture debate. Another interesting aspect of this debate looks at how much either of these concepts is incorporated into our health, for conditions such as heart disease and schizophrenia. Last year, I even actually found out that the way they studied Nature vs. Nurture was by separating identical twins by placing them in different environments, and seeing whether or not the change in the environment (Nurture) will impact their likelihood of inherit tendencies and medical conditions that were demonstrated by their parents (Nature). At the conclusion of the study, they determined that they both play a part in many of these things, but it is nearly impossible to determine specifically which one contributes more.
  You may have never realized it, but you yourself have probably had or heard a conversation pertaining to the Nature vs. Nurture debate. Maybe someone has asked you if you think homosexuals are "born like that"? Well, that's what Nature vs. Nurture! I find it to be an interesting and thought-provoking thing to think about whether people are already born knowing what their sexual orientation is, or whether it is decided post-conceivement. I pose this question to you, and ask you not to just make up you mind or take the position that you already have; I am challenging you to really think about it. If you think it is inborn, why do you feel that way? What pushes you to feel that a newborn, who knows nothing of the world that it was born into, would yet already know what his/her sexual preference is? And if you think it is something that is realized post-conceivement, specifically how to do you think it is "learned"? Do you think sexual orientation is adapted from those surrounding you, or is it something you just figure out on your own?
  I'm not going to lie; I don't even have a concrete standpoint on the above issue. If I had to say something about it, I would have to agree with psychology's conclusion that it's a little bit of both. And although it isn't an easy thing to actually consider, I am posing such a complicated question to you all because I'm confident that you are all intelligent and capable of doing such mature, in-depth, responsible thinking about a subject as controversial as this. (But maybe don't think about it for too long...it is REALLY complicated, and my head actually started hurting after prolonged thought about it.)
  Let me know your thoughts and responses--I'm definitely interested in hearing what people of both the young and the older generations have to say about such things.
  Happy Thinking!