* 5. Loftus’ “Lost in The Mall” Study
In 1995 and ‘96, Elizabeth Loftus, James Coan and Jacqueline Pickrell documented how easy it was to implant in people a fictitious memory of having been lost in a shopping mall as a child. The false childhood event is simply described to a participant alongside true events, and over a few interviews it soon becomes absorbed into the person’s true memories, so that they think the experience really happened. The research and other related findings became hugely controversial because they showed how unreliable and suggestible memory can be. In particular, this cast doubt on so-called “recovered memories” of abuse that originated during sessions of psychotherapy. This is a highly sensitive area and experts continue to debate the nature of false memories, repression and recovered memories. One challenge to the “lost in the mall” study was that participants may really have had the childhood experience of having been lost, in which case Loftus’ methodology was recovering lost memories of the incident rather than implanting false memories. This criticism was refuted in a later study (pdf) in which Loftus and her colleagues implanted in people the memory of having met Bugs Bunny at Disneyland. Cartoon aficionados will understand why this memory was definitely false.
* 8. The Kirsch Anti-Depressant Placebo Effect Study
In 2008 Irving Kirsch, a psychologist who was then based at the University of Hull in the UK, analysed all the trial data on anti-depressants, published and unpublished, submitted to the US Food and Drug Administration. He and his colleagues concluded that for most people with mild or moderate depression, the extra benefit of anti-depressants versus placebo is not clinically meaningful. The results led to headlines like “Depression drugs don’t work” and provided ammunition for people concerned with the overprescription of antidepressant medication. But there was also a backlash. Other experts analysed Kirsch’s dataset using different methods and came to different conclusions. Another group made similar findings to Kirsch, but interpreted them very differently – as showing that drugs are more effective than placebo. Kirsch is standing his ground. Writing earlier this year, he said: “Instead of curing depression, popular antidepressants may induce a biological vulnerability making people more likely to become depressed in the future.”
* 9. Judith Rich Harris and the “Nurture Assumption”
You could fill a library or two with all the books that have been published on how to be a better parent. The implicit assumption, of course, is that parents play a profound role in shaping their offspring. Judith Rich Harris challenged this idea with a provocative paper published in 1995 in which she proposed that children are shaped principally by their peer groups and their experiences outside of the home. She followed this up with two best-selling books: The Nurture Assumption and No Two Alike. Writing for the BPS Research Digest in 2007, Harris described some of the evidence that supports her claims: “identical twins reared by different parents are (on average) as similar in personality as those reared by the same parents … adoptive siblings reared by the same parents are as dissimilar as those reared by different parents … [and] … children reared by immigrant parents have the personality characteristics of the country they were reared in, rather than those of their parents’ native land.” Harris has powerful supporters, Steven Pinker among them, but her ideas also unleashed a storm of controversy and criticism. “I am embarrassed for psychology,” Jerome Kagan told Newsweek after the publication of Harris’ Nurture Assumption.
* 10. Libet’s Challenge to Free Will
Your decisions feel like your own, but Benjamin Libet’s study using electroencephalography (EEG) appeared to show that preparatory brain activity precedes your conscious decisions of when to move. One controversial interpretation is that this challenges the notion that you have free will. The decision of when to move is made non-consciously, so the argument goes, and then your subjective sense of having willed that act is tagged on afterwards. Libet’s study and others like it have inspired deep philosophical debate. Some philosophers like Daniel Dennett believe that neuroscientists have overstated the implications of these kinds of findings for people’s conception of free will. Other researchers have pointed out flaws in Libet’s research, such as people’s inaccuracy in judging the instant of their own will. However, the principle of non-conscious neural activity preceding conscious will has been replicated using fMRI, and influential neuroscientists like Sam Harris continue to argue that Libet’s work undermines the idea of free will.