majdx003: October 2011 Archives

Does media violence cause real-world aggression? Although psychologists have differing opinions regarding correlation vs. causation, most can agree that media violence is a contributing factor.
(in case link above doesn't work:

Correlation vs. Causation: Through correlational designs, data has shown that children who watch violent TV shows are more aggressive than those who don't. However, this doesn't necessarily indicate a direct causation between the two. A third variable, like initial aggressiveness levels, could affect a kid's choice on whether or not to tune in to an aggressive TV show.

Ruling Out Rival Hypotheses: Longitudinal designs have also shown a relationship between media violence and real-world aggression; kids who watch violent TV shows commit more crimes than kids who don't, even if their initial aggression levels are similar. But is it a direct causation? No, because longitudinal designs aren't really experiments. The kids aren't randomly selected or assigned to a particular TV show; instead, they choose which shows to watch. Also, there can be many confounding variables like lack of parental supervision and boredom with regular TV shows that might contribute to this correlation.

Ruling Out Rival Hypotheses: In a field study conducted by David Phillips, it was discovered that homicide rates rose 12.5% after widely publicized boxing matches. This surprising information led people to believe that violent boxing matches caused a rise in homicide. However, psychologists realized that the relationship between these two occurrences could have been due to chance, because there are numerous other reasons why homicide rates increase.

Ruling Out Rival Hypotheses: In another field study, a town without TV access (A) was compared to a town with TV access (B). Initially, town A was less aggressive than town B. However, after enabling TV access to town A, the once media-free town became more aggressive. This shows a correlation between media violence and real-world aggression, but other factors could've influenced this relationship. For instance, after this field study began, the Canadian government constructed a highway that connected town A to town B. Because town A wasn't isolated anymore, town B could have negatively influenced kids by exposing them to things like crime.

Even though there are confounding variables in the relationship between media violence and real-world aggression, many psychologists agree that media violence contributes to aggression. However, psychologists can't confirm that there's a direct causation between the two.

This relates to college students, because so many shows we watch and video games we play depict violent acts of killing each other. Just look at the top video games sold in recent years: Gears of War 3, Dead Space 2, Twisted Medal, Halo Reach and many more. It's good to know that other factors affect the relationship between media violence and real-world aggression, because otherwise most people would become violent.

Lilienfeld textbook chapter 6

Stages of Sleep

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In 1951, an important discovery was made at the University of Chicago. Nathaniel Kleitman's grad student monitored a sleeping boy's brain waves and eye movements and discovered that, every so often, the boy's eyes darted from side to side and his brain activity fluctuated. From these findings, Kleitman concluded that there are five stages of sleep.

Stage 1 sleep is the lightest stage of sleep, lasting anywhere from five to ten minutes. During this stage, the brain relaxes by about 50% and produces theta waves, which occur four to seven cycles per second. If you've ever jolted awake due to a sudden sense of falling or felt very confused after waking up, chances are you were in this stage of sleep.

Stage 2 sleep is where we spend 65% of our sleep time. Although the brain continues to relax, occasional bursts of electrical activity, called sleep spindles, occur twelve to fourteen cycles per second. Also, K complexes appear. During this stage, heart rate and body temperature decrease, muscles relax, and eye movements stop.

Sleep stages 3 and 4 are the deepest stages of sleep. In these stages, delta waves become prevalent and occur one to two cycles per second. In stage 3, these waves happen 20% to 50% of the time, and in stage 4, they happen over 50% of the time. In order for us to have a fulfilling night's sleep, we have to experience these two stages of sleep.

Stage 5 sleep is called rapid eye movement (REM) sleep. Here, we dream vividly and more often than in any other stage. During this stage, the brain kicks into high gear and produces waves that look like those of wakefulness. Heart rate and blood pressure increase, and rapid and irregular breathing occurs. We're in this stage for about 20% to 25% of our night's sleep.


Stages of Sleep video

As college students, most of us don't get enough sleep due to homework assignments, studying for tests, and participating in extracurricular activities. We might think that sleep isn't as important as getting good grades in our classes, but we're wrong. It's important that people get enough sleep each night, because sleep reduces stress, improves our memory, and reduces our chances of developing a physical or mental disorder.

Chapter 5 of our Lilienfeld Psychology book

The 10% Myth

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With the evidence we have today, the myth that we only use 10% of our brains sounds ridiculous. But back in the day, why did so many people believe it?

Nobody knows exactly how this myth started, but some psychologists believe Karl Lashley had something to do with it. In the 1920s and 30s, Lashley did many experiments on rats; he would make them learn a task with their brains intact, then he would remove large portions of their brains and make them redo the task (Washington). His results showed that the even without most of their brain, the rats could still accomplish the task. Therefore, Lashley concluded that most of the brain is unused and unnecessary. Another psychologist that contributed to this myth is William James. In the 1900s, James was discussing the brain and said, "The average person rarely achieves but a small portion of his or her potential" (How Stuff Works). From these men, the idea that people only use 10% of their brain was spread across the world.

In more recent years, psychics and major national companies have publicly announced their agreement with the myth that humans only use 10% of their brains. Psychics Caroline Myss, Uri Geller, and Michael Clark have all stated that everyone has the potential of psychic powers, but people don't know how to tap into it since they only use 10% of their brains (Snopes). In 1998, a U.S. Satellite Broadcasting ad showed a picture of a brain and the words, "You only use 11 percent of its potential" (Snopes). Because the ad was on television and from a seemingly reliable source, many people believed the myth.

However, it has been proven that we use more than 10% of our brains. Since there is no way to test the ability of psychic powers, psychologists consider this to be an extraordinary claim. In addition, with the availability of different types of brain imaging machines, it can be physically proven that humans use their whole brains (Snopes). Brain scans have shown that regardless of what people are doing, their brains are always active. An inactive part of the brain would only occur if it was brain damaged (How Things Work). These are solid ways to prove that humans use more than 10% of their brains.

Sources: (Snopes) (Washington) (How Stuff Works)

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