Hi Scott- Good question! I think that the interpretation would hinge on whether one could postulate a reasonable underlying causal mechanism which could moderate the effect differently in the two groups. If so, then I would favour the interaction explanation, but I would also want to test the hypothetical effect (if possible). Re the Sharkey study, I don't see a clear enough causal mechanism which would account for the difference. It's an interesting finding, but I'd want to see a replication before I bought into the premise. That's my $.02 worth. I'll be interested in hearing what others have to say.
-Don. ----- Original Message ----- From: "Lilienfeld, Scott O" <[email protected]> Date: Monday, June 14, 2010 3:16 pm Subject: RE: [tips] a recent corr/causation example To: "Teaching in the Psychological Sciences (TIPS)" <[email protected]> > This study, which I haven't read, raises another question (in > addition to the correlation-causation question) that I always > find interesting to ponder...when does detecting an effect in > one group (e.g., African-Americans) but not another (e.g., > Hispanics) constitute a legitimate statistical interaction vs. a > failed replication? And is the author justified in > interpreting it as the former rather than latter, as he seems to > be? It's something I struggle with, and I'd be > curious to hear others' thoughts. ....Scott > > > Scott O. Lilienfeld, Ph.D. > Professor > Editor, Scientific Review of Mental Health Practice > Department of Psychology, Room 473 Psychology and > Interdisciplinary Sciences (PAIS) > Emory University > 36 Eagle Row > Atlanta, Georgia 30322 > [email protected] > (404) 727-1125 > > Psychology Today Blog: http://www.psychologytoday.com/blog/the- > skeptical-psychologist > > 50 Great Myths of Popular Psychology: > http://www.wiley.com/WileyCDA/WileyTitle/productCd-140513111X.html > > Scientific American Mind: Facts and Fictions in Mental Health Column: > http://www.scientificamerican.com/sciammind/ > > The Master in the Art of Living makes little distinction between > his work and his play, > his labor and his leisure, his mind and his body, his education > and his recreation, > his love and his intellectual passions. He hardly knows > which is which. > He simply pursues his vision of excellence in whatever he does, > leaving others to decide whether he is working or playing. > To him - he is always doing both. > > - Zen Buddhist text > (slightly modified) > > > > From: David Hogberg [mailto:[email protected]] > Sent: Monday, June 14, 2010 6:01 PM > To: Teaching in the Psychological Sciences (TIPS) > Subject: [tips] a recent corr/causation example > > > > from today's Reuters Health Report: > Murder rates affect IQ tests scores: study > Maggie > Fox<http://blogs.reuters.com/search/journalist.php?edition=us&n=maggie.fox&;>, > Health and Science Editor > WASHINGTON > Mon Jun 14, 2010 5:36pm EDT > > > WASHINGTON (Reuters) - A murder in the neighborhood can > significantly knock down a child's score on an IQ test, even if > the child did not directly witness the killing or know the > victim, U.S. researchers reported on Monday. > > > <http://www.reuters.com/news/us> > > The findings have implications both for crime control efforts > and for the heavy reliance on standardized tests, said New York > University sociology professor Patrick Sharkey, who conducted > the study. > > They can also explain about half the achievement gap between > blacks and whites on such tests, he reported in the Proceedings > of the National Academy of Sciences. > > "It means being more aware of the potential for violence to have > a reach that extends beyond just those victimized and those who > witness a violent event, to reach across a community and affect > all children in a community," Sharkey said in a telephone interview. > > Sharkey compared data on crimes broken down to within a few > blocks in a neighborhood with school test scores. > > He collected details of more than 6,000 murders in the Chicago > area and the results of two surveys of children and families in > Chicago neighborhoods. The surveys included scores from tests > that are used to determine a child's IQ. > > If a murder occurred in a child's neighborhood -- an area of > roughly six to 10 square blocks as denoted by the U.S. Census -- > the children's test scores fell by an average of half a standard > deviation, Sharkey reported. > > On an IQ test using 100 as the average or norm, one standard > deviation is 15 points. So if a child took the test within a > week of a local murder, his or her score was 7-8 points lower on > average than the score of a similar child in a similar > neighborhood where there was no murder. > > This fits in with what is known about the effects of post > traumatic stress, Sharkey said. "The results suggest that > children may carry the burden of violence with them as they take > part in daily life within the neighborhood or school settings," > he said. > > PASSING EFFECT > > The effects wear off after a week to nine days, Sharkey found. > But in areas with a lot of crime, this does not provide much relief. > > "When one takes into account the prevalence of homicide in the > most violent neighborhoods in cities like Chicago, these results > mean that some children spend about one week out of every month > functioning at a low level as they navigate the home or school > environment," he said in a statement. > > In general, black U.S. children score about one standard > deviation lower on standardized tests than white children. This > finding accounts for half that difference, Sharkey said. > > He was unable to find enough murders in predominately white > neighborhoods to see if white children were affected. > > Curiously, there were enough murders in Hispanic neighborhoods > but Latino children seemed unaffected. > > "I just didn't find the same effect," Sharkey said. > > It could be the Hispanic children did not identify with the > violence, Sharkey added. "Most of the victims, even in the > Hispanic neighborhoods, were black." > > It is well documented that blacks are far more likely to be > murdered than members of any other U.S. ethnic group -- murder > is the most common cause of death for young black men. > > Sharkey said the findings also have implications for IQ tests, > which are supposed to be neutral assessments of ability. > > "These tests are not purely capturing some underlying > intelligence," he said. > > > -- > David K. Hogberg, PhD > Professor of Psychology, Emeritus > Department of Psychological Science > Albion College > Albion MI 49224 > > Tel: 517/629-4834, Mobile: 517/262-1277 > > --- > > You are currently subscribed to tips as: > [email protected]<mailto:[email protected]>. > To unsubscribe click here: > http://fsulist.frostburg.edu/u?id=13509.d0999cebc8f4ed4eb54d5317367e9b2f&n=T&l=tips&o=3082 > (It may be necessary to cut and paste the above URL if the line > is broken) > > or send a blank email to leave-3082- > [email protected]<mailto:leave-3082-13509.d0999cebc8f4ed4eb54d5317367e9...@fsulist.frostburg.edu> > > ________________________________ > This e-mail message (including any attachments) is for the sole > use of > the intended recipient(s) and may contain confidential and privileged > information. If the reader of this message is not the intended > recipient, you are hereby notified that any dissemination, > distributionor copying of this message (including any > attachments) is strictly > prohibited. > > If you have received this message in error, please contact > the sender by reply e-mail message and destroy all copies of the > original message (including attachments). > > --- > You are currently subscribed to tips as: [email protected]. > To unsubscribe click here: > http://fsulist.frostburg.edu/u?id=13157.966b795bc7f3ccb35e3da08aebe98f18&n=T&l=tips&o=3083or > send a blank email to > leave-3083-13157.966b795bc7f3ccb35e3da08aebe98...@fsulist.frostburg.edu Don Allen Retired professor Langara College --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=3084 or send a blank email to leave-3084-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
