Start by giving a detailed definition of what correlation is. Then answer:
What are the different types of correlation? Now for the technical area: How is the strength of a correlation determined? Then consider anxiety and depression. If anxiety and depression are correlated, what three possible directions of causality might explain this correlation
Correlation is simply a measure of how two variables are related to one another. You may find it easier to think of it as the way to that two variables change together. We can have one variable increase while the other decreases (for example, we may expect this if we're looking at the correlation between body temperature and time spent outside on a cold day). Or we can have two variables increase together (for example, age and years spent in school). It is important to note that correlation does NOT ever imply causation - just because we have a relationship between variables does not mean that the change in one caused the other to occur. Sometimes this may be tempting to conclude (e.g. with the example of body temperature and time outside), but such a conclusion would not be justified without an experimental manipulation.
I'm not sure exactly what you mean by different 'types' of correlation, so I'm going to give you two answers for this part. You can pick the one that you meant.
1) We can have positive, negative, strong, and weak correlations. A positive correlation means that both variables increase together (see age and education example above). A negative correlation means that as one variable increases (e.g. time spent outside), the other decreases (e.g. body ...