correlations in psychology

Rxy in Psyc

One of the biggest mistakes we make as individuals is to see that two things occur together and conclude that one causes the other. For instance, there is a great deal of information online and in other venues about depression and poor diet. For example, a self-help depression website offers this quote from a book on the subject "Food can affect your mood, and what you choose to put into your mouth can influence your state of mind" (http://www.depression-help-for-you.com/diet-for-depression.html). Now that may have some truth to it as one may feel better after a good meal and not so good after eating burned popcorn, but the site goes on to explain how studies have found relationships between higher rates of depression and consumption of junk food, soda, etc. Interestingly there is a huge market for books that promote diet for depression, the implication being that depression is caused by a poor diet and eating right will relieve depression. Amusingly I suppose none of these authors ever read the diagnostic criteria for depression that indicate that poor eating habits are a symptom of depression, not a cause of it, suggesting when one is severely depressed one of the manifestations is a change in diet nor have they considered that a large number of Americans eat poor diets, and yet millions do not get depressed.

Another well-documented relationship is that between low self-esteem and grades in elementary school students. It appears that a lot of students that do not do well in school score poorer on measures of self-worth and so forth. The popular media has jumped on studies like this claiming make kids feel better about themselves and their grades will improve. Self-esteem has been popularized as a cure-all for everything-raise self-esteem and all is well! However, could it be that poor grades affect self-esteem? Lilienfeld, Lynn and Lohr (2003) discuss the whole self-esteem relationship including the grade issue, substance abuse, delinquency, etc. The findings indicate that the grade and self-esteem relationship is spurious and that having chronically poor grades is more likely to lead to issues with self-confidence than vice versa. In other issues such as substance abuse and delinquency the low self-esteem issue appears to surface in most of these individuals after they are caught or exposed, not before their transgressions (the third variable effect). However, watch talk-shows on the subject and no one is convinced; low self-esteem is still considered a major causal factor by the media.