A lot of the time, people cite studies to prove their points. Trouble is, there is a study for every statement. If you say “here’s a study that proves I’m right”, the opponent can go “Nuh-huh, here’s a study that shows I’m the one who’s right”.
One should not put all one’s faith into one study. The quest for truth about people’s psychology is found through lots of studies, which eventually will provide us with a big picture of how things really are. There are things to think about when looking at a study:
1) Correlation doesn’t imply causation. Duh. That’s probably obvious. Correlation studies (f. ex.: a sexist attitude associated with loving bigger boobs on women) don’t establish causation. Hey, maybe loving bigger boobs causes a sexist attitude, or both things are caused by some hidden variable? The only way to establish causation is to conduct an experiment where all variables are kept fixed, except the one you suspect is the one responsible for causation.
2) Is the study well-designed? To form a conclusion about the population, you need to pick a random sample from it, and measure whatever you want to measure.
3) Even if the study is well-designed, there is always a small chance the results will be wrong due to chance (random error) alone. If the study was replicated with similar results, its validity is strengthened.
4) Does the study (if it’s an experiment) have external validity? That means the degree to which the results can be generalized to other populations, settings and conditions. To figure that out, many studies on the same topic are often gathered and analyzed together. The resulting meta-analysis makes conclusions based on all of the studies it used.
5) How does the study fit into the big picture of things? In short, do the results make any sense? Can they be possible, and are they probable, if what you know is true? Unfortunately we can’t overly rely on our personal experiences to answer those questions, as personal experiences are often self-selected and badly documented. I think one has to study psychology to get any good at judging studies and people’s statements about what is true for human nature, and what is not. One also has to at least take an elementary statistics course, to get a clue of what good studies are supposed to be like. Right now, I will even say that you can’t make that many reasonable conclusions about anything unless you study psychology properly. I recommend getting a few textbooks and studying them to get a bird’s view of the subject, before getting into details. I got these and they are very good:
1) Psychology: The science of mind and behavior, N. Holt, A. Bremmer, E. Sutherland, M. Vliek, M. Passer, R. Smith, 2nd ed.
2) Introduction to the Practice of Statistics, Moore, McCabe, Craig, 7th ed.
One major thing I noticed when studying psychology is how scientific it really is, and how terrible it makes Gender Studies look. Psychology takes into account EVERYTHING that creates our personality and behavior: biology, environment and our own thought processes.