Hi, I’m Michael Corayer and this is Psych Exam Review. In this video I want to consider the role of culture on perception. So in the previously videos we’ve seen that learning plays a role in our perception. We have to learn how to perceive, we have to figure out how to make sense of the information coming in from our senses. We learn how to interpret and organize this information. Now if we have to learn how to perceive then this opens up the possibility for social and cultural influence because our culture can influence our learning and then our learning can influence how we perceive the world. Let’s look at an example of this. This is a famous example called the Müller-Lyer illusions. This is an illusion created by a German sociologist named Franz Carl Müller-Lyer OK so this Müller-Lyer illusion you may have seen before, so we have just a straight line here and now I’m going to copy this line so that you know that the second line is identical. Here’s a copy of this line, you can see these are exactly the same length. Now I’m going to go in and just add some tails on this one. And I’m going to add some tails on this one. When I do this we now have this illusion that the top line appears to be longer than the bottom line. This is the Müller-Lyer illusion. It’s very simply but it’s powerful, you look at it and it really does feel like the top line is longer. So how might this relate to culture? A researcher named Marshall Segall and colleagues decided to go out and test this. They wanted to see if people from different cultures experienced this illusion in the same way. They went around to a number of different cultures and they showed people this illusion and they found that some people were more susceptible to the illusion than others. So what made a certain cultural group more susceptible to the illusion? They proposed what’s called the carpentered-world hypothesis. The carpentered world hypothesis is the idea that people who live in a more “carpentered” world are more susceptible to the Müller-Lyer illusion. So what do I mean by a “carpentered world”? This refers to a world that has a lot of artificial, created structures things that are carpentered. So you’re going to see lots of right angles, parallel lines converging, right? If you think about most of the things that you see most of your experience in buildings is a very carpentered world. There’s lot of right angles. You don’t see lots of right angles in nature. But in a carpentered-world they’re all over the place. You see parallel lines converging every time you look down a hallway, every time you look into a room, which is most likely a square or rectangular room, we don’t have lots of rounded walls. As a result you’ve learned to make assumptions about the lines that you see. You’re constantly seeing parallel lines converging. You’re constantly seeing right angles making corners in rooms and as a result, those assumptions that you’ve learned how to make influence the lines that you see in the Müller-Lyer illusion. Let’s look an example of how this might actually be applied to a real life situation. We can see a real situation that actually looks quite similar to the Müller-Lyer illusion. So again we’re going to draw a straight line. Ok, so here’s our line. Again I’m going to copy it so we know that it’s the same. Put this one here. We’ll use a different color for this to stand out a bit. Okay so the idea here imagine we’re sort of looking into a room here, this is a carpet or something. The idea is that this is sort of situation we might see frequently. We’re looking back into the corners of a room, I haven’t drawn this quite perfectly here, but the idea is this is the back wall here and this is some rug sitting here and we’ve learned that obviously this back wall here is much longer than the rug here. We’re assuming the room, these are parallel lines that appear to converge because of linear perspective. The idea is that we’re so used to seeing this type of situation where our brain makes the assumption “OK these two lines on my retina are the same length but I know that this one is farther away and therefore I know it must actually be longer”. We sort of exaggerate this difference and this creates the illusion. This you can see is quite similar to that Müller-Lyer illusion. We have the tails sticking out on this one and sort of sticking in on this one. The idea is that that’s the explanation for this illusion. I’ll show you one other demonstration of this. This is one of my favorite illusions because it’s very easy to draw but very powerful. You can see it appearing as I draw. It operates on the same principle. We’re going to draw two lines here. There’s a straight line and let’s go ahead and copy this. Oops, that’s our line from before. Try that again. I don’t know what’s happening here. That’s annoying. There we go. Ok. Copy that one. So these lines are the same length. Now we’re just going to go in and add some other lines. As I do this you might start getting the feeling that that line on the right is getting longer. Now hopefully you have this same sort of experience where this line here seems to be longer than this one, even though you know they’re identical. What’s happening here? Again, it’s using this idea of linear perspective, parallel lines converging, and the idea that this line is farther away from you. You’re so used to seeing this sort of situation in the world you make assumptions that this one, even though it looks the same on my retina, this one’s a lot farther away therefore it must be bigger, therefore you start to see it as actually being bigger. So that’s another demonstration of this carpentered-world hypothesis for potentially explaining something like the Müller-Lyer illusion. Again, it’s very similar in that we have essentially, there’s the lines that are sort of inverted one, here’s the sort of outward one and so that this would explain this Müller-Lyer illusion. OK so that’s the carpentered-world hypothesis and one possible example of how culture can influence our perception. I hope you found this helpful, if so, please like the video and subscribe to the channel for more. Thanks for watching!