Google is your friend. There are many branches of psychology...research clinical and experimental psychology. Research education requirements for different positions. You'll find that a Master's is a must, while a PHD/PsyD would give you a huge advantage and more carreer opportunities.
Psychology has always interested me from the beginning because it is always changing. From my point of view, the more people have sex, the more babies are born with mental illnesses and disorders.
It is only logical that as the population grows and more babies are being born, there will more babies with disorders. What you want to pay attention to is the proportion of babies born with mental illnesses and disorders. Look at this ratio:
babies born with disorders and illnesses
total babies born in that time period
Is the ratio higher for 2011 than it was for 2010? Is it higher for 2011 than it was for 2001? If so,
what might be causingthe increase in proportion of babies born with disorders and illnesses? Pay attention to the mothers who had the babies. Are they doing more prescription or illicit drugs? Having babies at a younger age?
You need to define your birth defect of interest, population of interest, and time period of interest. Perhaps you want to look at cleft palate births in the USA between 2001-2011. Here's a little info about the causes of cleft lip/cleft palate:
http://www.mayoclinic.com/health/cleft-palate/DS00738/DSECTION=causes . Notice the environmental factors causing the condition:
Fetal exposure to cigarette smoke, alcohol, certain medications, illicit drugs and certain viruses have been linked to the development of a cleft. "Certain medications" sticks out at me, because if a pregnant mother was prescribed a drug and told it wouldn't harm her baby, but the drug caused the baby to have cleft lip/palate, then that is terrible and research needs to be done to make sure that pregnant women are not given the drug in the future.
This is all just trying to give you a good idea about what psychology is, as there is already ongoing research on this issue.
Would you prefer to do something like that for your master's/PHD/PsyD, or would you rather go the clinical route? If you think you'd be a good clinical psychologist and you have great people skills, you're in luck, because you can have a great career as a clinical psychologist with only a Master's. I spoke with a clinical psychologist the other day. He has a PHD and makes great money, but he says there are younger guys in his building with only their Master's, who make just as much or more money than he does. He wasn't bitter about it, just pointing out a fact...perhaps trying to sway me away from my persuit of a career in social work.
Psychology is relatively new as a true science. If you say it is "one of the oldest sciences in the world," it can only be in the sense that there were probably caveman therapists. Instead of ignoring the depressed cavemen/women in their family, they helped them through their problems with communication and affection. This helped improve the family's chance of survival. At this point psychology was far from a science, however. Research, research, research. Google is your friend, and so is the Bluelight search feature.