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False Memories

Particularly in this age of Google, Wikipedia, YouTube, and the internet, you can’t believe everything you read, hear or see. Moreover, according to Ben Goldacre even memory can be dramatically wrong. Goldacre refers to an article by de Vito, et al and should be read in its entirety. "On an abstract level, there's a good short report in the journal Cortex, where researchers in Bologna demonstrate the spectacular hopelessness of memory. One morning in 1980 a bomb exploded in Bologna station: 85 people died, and the clock stopped ominously showing 10.25, the time of the explosion. This image became a famous symbol for the event, but the clock was repaired soon after and worked perfectly for the next 16 years. When it broke again in 1996, it was decided to leave the clock showing 10.25 permanently, as a memorial."

The clock at the Bolgna railroad station stopped at
10.25 to mark the time of the terroristic massacre

"The researchers asked 180 people familiar with the station, or working there, with an average age of 55, about the clock: 173 knew it was stopped, and 160 said it had been since 1980. What's more, 127 claimed they had seen it stuck on 10.25 ever since the explosion, including all 21 railway employees. In a similar study published last year, 40% of 150 UK participants claimed to remember seeing closed circuit television footage of the moment of the explosion on the bus in Tavistock Square on 7 July 2005. No such footage exists."

Discussion 1. Goldacre is an excellent writer who specializes in pointing out how statistics is misused in science. Go to here for his 2009 contributions. To get to previous years merely change the "9" to "8" or "7" etc. 2. One would imagine that those closest to an incident would have the best memory but de Vito points out: “From the 173 people who knew that at the time of testing the clock was stopped, a subgroup of 56 citizens who regularly take part in the annual official commemoration of the event has been further considered: only six (11%) of them correctly remember that the clock had been working in the past.” 3. Memories can be repressed as well as false. Go to here for a discussion of repressed memory relating to child abuse; specifically, you will find 1.Smile Intensity and Divorce

Is there a connection between positive expressive behavior, as seen by facial photographs, and success in avoiding divorce? According to Moskowitz], “If you want to know whether your marriage will survive, look at your spouse's yearbook photos. Psychologists have found that how much people smile in old photographs can predict their later success in marriage.” This claim is based on a study headed by Matthew Hertenstein detailed in the April 5 issue of the journal Motivation and Emotion. The table below is taken from Hertenstein’s publication. Study 1, Sample 1 involves alumni who were psychology majors at a particular university; Study 1, Sample 2 involves alumni from the same university who were not psychology majors. In each instance, the participants submitted yearbook photos which were judged for smile intensity and whether or not the participants were divorced or still married. Study 2 is similar but involved older members of the community who submitted photos from decades past.


1. In the above table, a two sample t-test of means (“M”) is carried out for each row. Pick a row and verify degrees of freedom (“df”), the value of t and the p-value (“p”). Note that “p values are one-tailed given the directional hypothesis of the studies.”

2. While p-value is useful to some extent, “effect size” may be of more interest. The last column, “r” signifies that some sort of correlation is taking place; it is sometimes called the point-biserial correlation coefficient. This correlation is between the independent dichotomous variable and the dependent variable (smile intensity). According to the psychology literature, it is given by

Where: rpbi = point-biserial correlation coefficient Mp = whole-test mean for those who stay married Mq = whole-test mean for those who get divorced St = standard deviation for all concerned p = proportion of those who stay married (i.e., those coded as 1s) q = proportion of those who get divorced (i.e., those coded as 0s)

Use this formula and Pick a row to verify the value in the table for “r”—ignore the sign.

3. Clearly, these results are for a sample. Speculate on what you would need to know of the characteristics of the participants in order to infer to a larger population.

4. Although the table is informative as to means and standard deviations, why would boxplots for each row be useful?

5. According to Moskowitz, but not mentioned in the paper itself by Hertenstein, “Overall, the results indicate that people who frown in photos are five times more likely to get a divorce than people who smile.” This comes about by looking at the highest scorers--who turn out to be mostly still married--compared to the lowest scorers who turn out usually to be those who are divorced. Why is this quotation featured rather than the above table? 6. For those who would like to improve their “smile intensity” of their photos, here is what the paper itself says the measurement process is: pened. 2. An event that you falsely remember can be psychologically equivalent to an event that really did happen. The clock in Milan worked for another 16 years. Adults report abuse which supposedly took place often decades previous. Use Google to see a discussion of some of these legal cases and their outcomes. 4. Is there anything you used to recall vividly that you now doubt actually occurred?