Everyone. In this video, we're going to be talking about correlations. It's very important to have at least a basic understanding of how correlations work because they're kind of the bread and butter of psychological research. We do a lot of correlational stats in psychology. A correlation is basically just a measure of the direction and strength of a relationship between two variables.

And we quantify them, turn them into a number using something called a correlation coefficient, also known as a Pearson's r. So if you see this little italicized r, you're typically looking at a correlation. We're going to go over what direction and strength mean separately. If we're talking about the direction of the relationship between two variables, what we're basically referring to is how these variables move in relation to each other. If we have a negative correlation, that means that our variables are moving in opposite directions.

So, for example, if our variables were parental sensitivity and children's anxiety symptoms. We might see that as parental sensitivity increases, children's anxiety symptoms decrease, indicating our variables are moving in opposite directions. That would give us a negative correlation. In contrast, we can have a positive correlation where our variables are moving in the same direction. For example, if our variables were parental sensitivity and children's well-being, those might be moving in the same direction, giving us a positive correlation.

It is important to remember that here, positive and negative do not mean good or bad. There's no moral value being assigned to these terms at all. You can have a positive correlation between, like, alcoholism and depression, for example. When we say positive or negative, all we are talking about is the direction of the relationship, basically just how these variables are moving in relation to each other. Okay.

So that is direction. Now we're going to move on to strength. If there is absolutely no correlation or no relationship between our variables at all, you are going to end up with an r of 0. Okay? Zero means that there is no relationship.

Now if we have an r of negative one or an r of positive one, those are what we call perfect correlations. An r of negative one is a perfect negative correlation and an r of positive one is a perfect positive correlation. You can see on these little charts, you can see how these data points are falling perfectly on those lines. It basically means that these variables are moving perfectly in sync with each other. That gives you a perfect correlation.

Now correlations of negative one and positive one almost never happen in real life in psychology research. So you can just think of them as the bookends on either side of our correlation spectrum here. No relationship, an r of 0.

A perfect relationship is going to be an r of positive one or negative one. When we're talking about the strength of a relationship, we're typically going to be describing our correlation as strong, moderate, or weak. These labels refer to the amount of dispersion in our data or how synchronized those variables are moving together. You can see here in our moderate graphs how we have a bit more spread in the data happening. They're clearly trending in the same direction, but they're not perfectly lined up on those red lines anymore.

Right? There's not so much synchrony. Whereas in these graphs that we have labeled weak, you can see there's quite a bit of distribution with these data points. They're really trending in the same direction but there's not a high level of synchrony there anymore. Now I'm sure you noticed that I did not put any numerical labels here, and that is because there is really no field-wide standard in psychology for what we consider a strong, moderate, or weak correlation.

This is going to differ among fields of psychology as well as different topics of study. And that's kind of annoying, but it just kind of is what it is. So if you begin to read psychological research and you notice inconsistent labels being used to describe the same correlation, you are not going crazy. There's just no standard. If I had to give you some numbers to kind of use as a jumping-off point, I would say often in psychology, correlations of 0.1 to 0.3 are typically described as weak.

Correlations of 0.3 to 0.5 are usually described as moderate, and then correlations that are higher than 0.5 are often described as strong. However, please don't take this as gospel. This is just kind of a starting-off point. Again, you will see different descriptors in different fields and among different areas of study. And I do want to be really clear, this applies to positive and negative correlations.

Okay? So the positive and negative sign is only telling you the direction of the relationship. The actual number is telling you the strength. Okay? So if we had a correlation of negative 6, that correlation is equally strong as a correlation of positive 6.

Okay? So these correlations would indicate that the variables are moving in different ways. Right? These variables are moving in opposite directions. These variables are moving in the same direction, but these correlations have an equal amount of strength.

Okay? Alright. So that is our little introduction to correlation, and I will see you guys in our next video. Bye bye.