Posts from the “Myths” Category

True or False: The timing of conception often determines the gender of your baby?

Posted on September 8, 2015

False.

I think it’s interesting that some couples try so hard to influence the potential gender of their children. There are supposedly lots of things that can impact whether conception results in a boy or a girl being born. The Chinese have a gender selection chart, or calendar, which suggests that conception occurring on certain days of the year will result in either male or female babies being born. Other possibilities include selecting certain positions during intercourse, eating certain types of foods, and even sleeping in certain positions. Medical personnel agree that the gender of a child is determined when a single sperm cell fertilizes an egg. The egg always carries an X chromosome while a single sperm can carry either an X (girl) or Y (boy) chromosome. So if a sperm cell that fertilizes an egg is carrying an X chromosome, a girl will be the conceived whereas a boy will be conceived if the sperm cell that fertilizes an egg is carrying the Y chromosome. Studies have shown that sperm with a Y chromosome (boys) are faster swimmers, but are not as strong and don’t live as long as sperm with an X chromosome. If you consider that conception usually occurs close to ovulation (most estimate a two to ten day range), it would stand to reason that timing could be a factor. For example, if intercourse occurs further away from ovulation, the sperm with the girl chromosome would likely have the advantage, due to a longer lifespan. However, this is not supported in the medical literature. The authors of one study published in the New England Journal of Medicine (1995) examined this topic and reported, “However, we found no association between the sex of the baby and timing of intercourse in relation to ovulation. We conclude that the deliberate timing of intercourse around the day of ovulation has no practical value in sex selection.”

Reference:

Wilcox, A., Weinberg, C., and Baird, D. Timing of sexual intercourse in relation to ovulation: Effects on the probability of conception, survival of the pregnancy, and sex of the baby. New England Journal of Medicine (1995), Vol 333, pp. 1517-1521.

Categories: Myths

True or False: You lose more heat through your head than any other part of your body?

Posted on September 3, 2015

False.

I regularly hear people talk about how we should keep our heads covered when we are in the cold because we lose lots of heat through our heads. I’ve heard numbers like fifty or even as much as seventy-five percent of the heat we lose is lost through our heads. The head makes up roughly eight to ten percent of the total surface area of the body, and heat loss through our head usually accounts for roughly eight or nine percent of the total amount of heat we lose. An interesting trend of late is men with any sign of hair loss or balding completely shaving their heads. When you see a shaved, completely bald and rounded shiny head, I can see how you might think that this would be an easy way for heat to leave the body. However, when we are in cold environments we will lose heat from any exposed areas of our bodies; the heat loss is about the same whether it comes from the head, arms, torso, or legs. It is true that the head and scalp have a very healthy blood supply; you’ve probably realized that if you’ve ever had a laceration or cut on your head or face—lots of blood! This might be one of the reasons that people think we proportionally lose more heat from our heads. Other reasons might include some early flawed military studies and statements about excessive heat loss through our heads in an army survival manual. One way researchers study this is to immerse participants’ heads in cold water and monitor body temperature. In a study by Bristow and colleagues (2006) published in the Journal of Applied Physiology, the authors state, “In conclusion, whole head submersion in seventeen degree water did not contribute relatively more than the rest of the body to total surface heat loss.” Ultimately, it’s not a bad idea to keep your head covered when you are out in the cold because it might help keep your ears from getting frostbitten, but remember that you don’t lose more heat through your head compared to other parts of your body.

Reference:

Pretorius, T., Bristow, G., Steinman, A., and Giesbrecht, G. Thermal effects of whole head submersion in cold water on nonshivering humans. Journal of Applied Physiology (2006), Vol 101, pp. 669-675.

Categories: Myths

True or False: Having babies listen to Mozart will make them smarter?

Posted on August 25, 2015

False.

Being parents of three children, I can tell you that my wife and I have had many of the same concerns and worries that millions of parents have had regarding their children’s intelligence and academic abilities. Why isn’t my child talking yet? When will she start reading? How are my child’s writing and math skills compared to their playmates? Should we send our child to an expensive private pre-school program? Is there anything else we can do to help “speed things up” academically for our children and give them that competitive edge as they take that monumental and daunting leap into kindergarten? I also remember considering playing classical music to our children when they were young because we had heard that it improves intelligence, something referred to as the Mozart effect. We didn’t opt for the expensive pre-schools and we didn’t make our kids listen to Mozart, and academically speaking they are doing just fine. The hype surrounding the Mozart effect, which now has a whole industry surrounding it with dozens of products and tens of millions of dollars in sales, started after a study on college students done in the early 1990’s showed that they performed better on a spatial reasoning task, a test where they had to fold and cut paper, after they listened to Mozart for ten minutes. Interestingly, this initial study did not include children or tests of intelligence. Many studies have since disproved the Mozart effect. Pietschnig and colleagues (2010) published a meta-analysis of dozens of studies that have been done to date and concluded that “In summary, this study shows that there is little support for a Mozart effect considering the cumulative empirical evidence.” In other words, exposing your children to Mozart or other classical music when they are in the womb, two months old, or two years old, will likely not increase their intelligence.

Reference:

Pietschnig, J., Voracek, M., and Formann, A. Mozart effect – Shmozart effect: A meta-analysis. Intelligence (2010), Vol 38, pp. 314-323.

Categories: Myths

True or False: There has been a tremendous increase in autism rates recently?

Posted on August 25, 2015

False.

Thinking back to my childhood, I can’t remember ever hearing the word autism or having a friend who was autistic. Today, however, most of us, even our children, know someone who has been diagnosed with autism. Gernsbacher and colleagues (2005) in an article published in the journal Current Directions in Psychological Science state that autism was first described as a standalone disorder in the 1940’s, but it wasn’t until 1980 that criteria for autism was included in the American Psychiatric Associations’ Diagnostic and Statistical Manual of Mental Disorders. The CDC describes Autism spectrum disorders (ASD’s) as a group of disorders that can result in social, communication, and behavioral challenges. The “spectrum” in ASD’s indicates the impact the disorder can have on an individual could be minor, or it could be very severe. The prevalence of autism appeared to dramatically increase in the early to mid 1990’s; however, it wasn’t clear if the increase was due to actual new cases of autism or increases in diagnosis and reporting. Some believe that Thimerosal, a mercury-containing compound in vaccines, is responsible for the increase in autism rates. However, there appears to be a lack of scientific evidence to connect the two. Additionally, in the article referenced above, Gernsbacher and colleagues discuss a variety of reasons they believe there has not been an epidemic of autism recently. The authors state that “no sound scientific evidence indicates that the increasing number of diagnosed cases of autism arise from anything other than purposely broadened diagnostic criteria, coupled with deliberately greater public awareness, and intentionally improved case finding.” So it appears that there truly has not been a dramatic increase in autism rates recently, simply changes in diagnostic criteria and public awareness.

Reference:

Gernsbacher, M., Dawson, M., and Goldsmith, H. Three reasons not to believe in an autism epidemic. Current Directions in Psychological Science (2005), Vol 14, pp. 55-58.

Categories: Myths

True or False: Most people experience a mid-life crisis?

Posted on August 18, 2015

False.

We often hear stories of individuals in their 40’s or 50’s who go through drastic life changes. Sometimes it’s a decision to get divorced, change jobs, move across the country, or maybe buy a sports car or even better a Harley Davidson. Often the explanation or blame for these behaviors falls to the individual having a mid-life crisis. Supposedly, many things can lead to someone’s having a mid-life crisis; some of the possibilities include unhappiness with a spouse, a lack of meaning or direction in one’s life, a feeling of unfulfilled goals or dreams, menopause, or simply a desire for fun, excitement, and adventure. I think it’s safe to say that many of the things that supposedly lead to a mid-life crisis regularly occur to people when they are in their 20’s or 30’s and even their 60’s or 70’s. I was unable to uncover any research that specifically described when a mid-life crisis usually started, how long it usually lasts, or the best way to get out of one should it occur. A study published in the Journal of Personality and Social Psychology by Reynolds, et al. (2001) suggests that as we get older positive affect, things like joy and excitement, remain fairly stable whereas negative affect, things like anger, disgust, anguish, and shame, actually decreases. The authors also discuss how additional research findings don’t support the idea that middle age is a time when many people go into crisis mode. They cite some studies showing that differences in life satisfaction change little across the lifespan and also discuss how some research actually supports the idea of greater well-being in older adults. While some people may go through hard times during the mid-life years, this is often the time when people are getting promoted, earning a decent salary, happily raising children, and generally feeling pretty good about themselves.

Reference:

Charles, S., Reynolds, C., and Gatz, M. Age-related differences and change in positive and negative affect over 23 years. Journal of Personality and Social Psychology (2001), Vol 80, pp. 136-151.

Categories: Myths

True or False: You spend less money when you use cash vs. credit cards?

Posted on August 17, 2015

True.

According to the website Creditcards.com, the average credit card debt in households that use credit cards is over $15,000, and there are over 500 million credit cards in circulation in the U.S. I knew that credit card debt was a problem for many people, but I didn’t realize just how big the problem was. If you own and use credit cards, you in all honesty can probably answer the question of whether you spend more money when using credit cards vs. using cash. My wife and I stopped using credit cards years ago. We never had a problem with carrying credit card debt, but we noticed that we spent roughly twenty to twenty-five percent more money when we made purchases with our credit cards vs. using cash. There have been a few research studies conducted on this topic, and most show that you indeed spend more money when you use credit cards, roughly eight to eighteen percent more. One early study was conducted by Elizabeth Hirschman (1979) and published in the Journal of Consumer Research. Dr. Hirschman hypothesized that consumers who only had bank- or store-issued cards would make larger total dollar purchases than those not possessing a card and that the average transaction with a card would be higher than transactions made with cash. The results of the study supported her hypotheses and showed that consumers did indeed spend more money and also made more purchases when using cards. One reason we might spend more money using credit cards is that it is much easier to make spontaneous purchases. Many years ago when my wife and I still had our credit cards, we were walking through a sporting goods store and happened past the firearms area. I’m still not sure how it happened, but in a matter of twenty minutes we purchased two firearms with the total bill being over a thousand dollars. We likely would not have made that purchase if we hadn’t had our credit cards in our wallets.

Reference:

Hirschman, E. Differences in consumer purchase behavior by credit card payment system. Journal of Consumer Research (1979), Vol 6, pp. 58-66.

Categories: Myths

True or False – The biggest shopping day of the year (in dollars spent) is the day after Thanksgiving?

Posted on June 22, 2015

False.

The Friday following Thanksgiving is known as Black Friday. Many consider this day to be the

“official” beginning of the holiday shopping season. It is common for stores to run huge promotions on Black Friday, sometimes slashing prices on large ticket items to get shoppers into stores. I’m someone who loves to read the paper and have a few (too many) cups of coffee in the morning. I’m always amazed by the size and weight of the paper the morning after Thanksgiving, due to the flyers and advertisements alerting potential shoppers of the deals that await them. It is also common to see news stories focusing on the hoards of shoppers often lined up in front of stores at 4 or 5 am waiting for the doors to open so they can get their deals. Regretfully, we also hear about fights, injuries and less commonly, even deaths associated with Black Friday. In 2008, an employee at a Wal-Mart was trampled to death as shoppers broke through the stores doors before the scheduled opening time. With all the attention given to Black Friday, it is easy to see why people might think it is the biggest shopping day of the year. Snopes.com, an urban legend website which is widely known for debunking myths and misconceptions, reports that Black Friday may be the day the greatest number of shoppers are visiting retail stores and shopping malls, it is not the biggest shopping day in regards to dollars spent. Traditionally, the day shoppers spend the most money is the Saturday before Christmas. I have to confess, that is the day I usually do ALL of my Christmas shopping, alongside many other people! So why the term Black Friday? Supposedly the term started to be used in Philadelphia in the 1960’s to describe the increased number of people and cars on the streets following the day after Thanksgiving. However, it is also often reported in the media that the term refers to the day that stores start to turn a profit (get into the black) in regards to their sales.

Reference:

http://www.snopes.com/holidays/thanksgiving/shopping.asp Website accessed 4-23-10

Categories: Myths

True or False – It really is true that opposites attract?

Posted on April 13, 2015

False.

When my wife and I met in college I was immediately attracted to her beautiful smile and friendly personality. As we started to date, I realized we were very different. She loved to read and could devour a book in a day or two; I usually read the minimum from my college textbooks to prepare for class and did no recreational reading. I was a bit of a sports fanatic; she likely couldn’t have told you the difference between a touchdown and a home run. She enjoyed watching TV shows and movies with her friends and I enjoyed ice fishing (we met in Minnesota) and walking through swamps pheasant and deer hunting. She was pretty laid back and didn’t let things bother her too much; I had a mild case of obsessive compulsive disorder and a definite type A personality. I could fill this page with all the ways we were different from each other. Is that why we were initially attracted to each other – our differences? I’d like to think it was my rugged handsomeness, but that probably wasn’t it. The topics of whether opposites attract and relational satisfaction have been well studied by researchers. Karney and Bradbury (1995) published a review article in which they examined many studies on marriage. In the article the authors stated that greater attitude and personality homogamy (similarity) between spouses predicts greater marital stability and satisfaction. Studies have also shown that even in the early stages of meeting and dating someone, we tend to be more attracted to people similar to us (think of the saying ‘birds of a feather flock together’). The same holds true for our friendships, we like to be around people who like the same things we do. No one is really sure where this myth came from, but we often hear of the good girl falling for the bad boy, and we frequently see this scenario (opposites attracting) in movie plots, remember the 1998 film You’ve Got Mail?

Reference:

Karney B & Bradbury T: The longitudinal course of marriage quality and stability: a review of theory, method, and research. Psychological Bulletin (1995), Vol 118, pps. 3-34.

Categories: Myths

True or False – Women talk three times as much as men?

Posted on March 30, 2015

False.

It is a popular stereotype that women talk more than men; many people think they talk a lot more. However, very little research has been conducted on this topic. In 2006, a woman by the name of Louann Brizendine published a book called The Female Brain. In the book she wrote that women speak about 20,000 words a day verses about 7,000 words a day for men. However, her claims were not supported by scientific studies. The only well designed study I could find which examined the number of words spoken between men and women was conducted by Mehl and colleagues (2007) and published in the journal Science. The authors studied nearly 400 college students over a seven year period. They used a device called an electronically activated recorder, EAR for short, to record words spoken throughout the day. The EAR device was set to record for thirty second every twelve and a half minutes participants were awake (this averaged about 17 hours a day). However, the device was set up in such a way so the participants didn’t know when the recording was taking place. When the study was completed, the authors learned that women spoke on average 16,215 words a day compared to 15,669 for men. So, women did speak slightly more words per day, but nowhere near 13,000 more. The fewest words spoken throughout the day was 700, and the most was 47,000. The participant who spoke 47,000 words a day was a male! The authors did report that women talked more about other people, and men talked more about concrete topics. If there is no scientific evidence that shows women speak more than men, how did this myth get so widespread? No one is really sure. One idea is that it originally came from marriage counselors, another from the notion that women often want to talk through their problems and men don’t.

Reference:

Mehl M, Vazire S, Ramirez-Esparaza N, Slatcher R, Pennebaker J: Are women really more talkative than men? Science (2007), Vol 317, pg 82.

Categories: Myths

True or False – We only use 10% of our brain?

Posted on March 16, 2015

False.

Imagine if you could take a supplement or complete a training program that would allow you to “unleash” the 90% of your brain that you currently don’t use! The truth is we really do use all of our brain. The 10 percent myth has been circulating for a long time. Many self-help gurus like people to think they only use a small capacity of their brain, as it enables them to sell lots of products and make a lot of money. It is thought that famed psychologist Williams James may have inadvertently started this myth when he stated that humans only achieve a portion of their true potential. Somehow 10% got attached to that statement and it morphed into we only use 10% of our brains. Then the 10 percent myth was mentioned in the preface of Dale Carnegie’s book How to Win Friends and Influence People, and that was likely how the myth got to be so widespread. Interestingly, many people still believe this myth. For example, the authors of one study (Higbee 1998) performed on college students (a relatively well educated population) reported that when participants were asked “About what percentage of their potential brain power do you think most people use?” over 31% of the students answered 10%. Brain imaging scans have revealed that all parts of our brain are in fact active. We may use different portions of our brains for different functions; so different parts of our brains may be active at different times, however, there are no black holes or dead spaces in our brains. It is well documented in the medical literature that injury or damage to a small area of the brain can result in devastating neurological consequences. So, rest assured even on days when it doesn’t seem like it, you are using all of our brain.

Reference:

Higbee K & Clay S: College student’s beliefs in the ten-percent myth. The Journal of Psychology (1998), Vol 132, pps. 469-476.

Categories: Myths