On 19 Nov 2009 at 10:57, [email protected] wrote: > I start teaching that some things are fairly set, such as > personality, and that these in-born characteristics determine > how others respond to us.
> I wish there were some strong data to support one side or another for most of > these things. I believe that > the behavior geneticists have a very strong set of evidence, as Scott noted, > that many human characteristics > are largely determined by nature. But if that's the case, then where do the > data come from that show that > abilities such as intelligence are mutable? These statements require qualification. It's not the case that personality is an in-born characteristic and "fairly set". In fact, if I recall correctly, estimates of heritability run at around 0.50 for personality, which leaves plenty of room for an environmental effect. The catch is that little or none of this is shared environment, and shared environment includes parental upbringing effects. The environmental component is almost entirely made up of non-shared environment--the unique experiences which are different for different members of the family. Judy Harris, in her second book _No Two Alike_ (2006) takes a crack at identifying how these non-shared environmental effects make people different (hint: it's not the parents). And I'm dearly hoping we won't hear from Joan on this book too. For IQ, the figure for heritability is generally found to be higher, typically in the 0.70 range, although there is a wide range of estimates. In school-aged children, while they are still at home, the figure is lower, and there is a clear shared environment effect. . So parents do seem to matter. But there's a catch which many don't seem to know about. This is only true in the child. As the child gets older and leaves the home, less and less of the environmental component can be attributed to shared effects, and as a adult, the shared component largely disappears. So parents matter at first to IQ, but later, very little. Stephen ----------------------------------------------------------------- Stephen L. Black, Ph.D. Professor of Psychology, Emeritus Bishop's University e-mail: [email protected] 2600 College St. Sherbrooke QC J1M 1Z7 Canada ----------------------------------------------------------------------- --- To make changes to your subscription contact: Bill Southerly ([email protected])
