flynn002

Today's Time Newsfeed carries a remarkable story: parents of children attending Catholic schools in Calgary were sent a special letter to accompany details of a vaccination programme against human papillomavirus (HPV), which protects against cervical cancer. In it, local bishops wrote: "Although school-based immunization delivery systems generally result in high numbers of students completing immunization, a school-based approach to vaccination sends a message that early sexual intercourse is allowed.” I find this amazing for several reasons: There's a complete failure to understand what affects teenagers' behaviour. Do the bishops seriously think that teenaged girls who are thinking of having sex say to themselves "Oh, wait a minute. I might get HPV. Let's not do it." Potential consequences of sex include a host of sexually transmitted diseases, as well as pregnancy. If these don't put girls off, then why should a risk of HPV?  HPV is a sexually tra...

Experimental psychology depends heavily on statistics, but psychologists don’t always agree about the best ways of analyzing data. Take the following problem: I have two groups each of 30 children, dyslexics and controls. I give them a test of auditory discrimination and find a significant difference between the groups, with the dyslexic mean being lower. I want to see whether reading ability is related to the auditory task. I compute the correlation between the auditory measure and reading, and find it is .42, which in a sample of 64 cases is significant at the .001 level. I write up the results, concluding that poor auditory skill is a risk factor for poor reading. But reviewers are critical. So what’s wrong with this? I’ll deal quickly with two obvious points. First, there is the well-worn phrase that correlation does not equal causation. The correlation could reflect a causal link from auditory deficit to poor reading, but we need also to consider other causal routes, as I’ll illus...

Based on: King & Bearman (2011) American Sociological Review, 76 (2), 320-346;  Data from birth and diagnostic records for all children born in California 1992-2000 Everyone agrees there has been a remarkable increase in autism diagnosis across the world. There is, however, considerable debate about the reasons for this. Three very different kinds of explanation exist. Explanation #1 maintains that something in our modern environment has come along to increase the risk of autism. There are numerous candidates, as indicated in this b logpost by Emily Willingham .  Explanation #2 sees the risks as largely biological or genetic, with changing patterns of reproduction altering prevalence rates, either because of assortative mating (not much evidence, in my view) or because of an increase in older parents (more plausible).  Explanation #3 is very different: it says the increase is not a real increase - it’s just a change in what we count as autism. This has been termed ‘di...