In my post on the above paper I made a number of criticisms, including that the paper should have been entitled “Adverse parenting and premature mortality”. My argument was that the family-related adversities were not truly external, and that genetic effects should have been considered. Read the whole thing here:
http://drjamesthompson.blogspot.co.uk/2013/09/childhood-adversity-and-lifespan.html
The corresponding author Michelle Kelly-Irving has kindly replied on behalf of all the authors, and I think it only fair to give this top billing as a separate item, so that subsequent comments can be appended as readers wish.
Parenting:
I don’t agree with you about the ACE measure being a proxy for parenting (or bad parenting). The measure aims to capture events that are likely to be stressful to a child, and that may have a permanent impact on their subsequent physiological reactions to stressful conditions. I agree that parenting is certainly implicated. However, should a child be separated from either parent through death or divorce is certainly not down to inadequate parenting. Similarly, a child who ends up in care is likely to be going through a stressful phase of their lives, but I’m not sure we can make the assumption about the parenting they received beforehand. It would make more sense to actually try to measure elements of parenting, which is certainly worth doing. There may be some variables in the NCDS that allow for this.
IQ:
At age 11 any measure of IQ is hugely confounded with socioeconomic and psychosocial circumstances. I am not clear as to what IQ would be measuring here – or ever, in fact.
Genetics:
The point that a prior variable linked to both ACE and premature mortality that we do not know about, or cannot take into account, is of course possible. That variable could be a genetic one. Genetics analyses using GWAS are not coming up with solid explanation for heritable traits. It is most likely a much more complex process of heritability than a mendelian-style genetic one, if there is something going on heritability-wise.
Parenting: "However, should a child be separated from either parent through death or divorce is certainly not down to inadequate parenting." Rather a weak point. The point made in my original comment was better; you could try separating bolt-from-the-blue parental death from deaths where the parent's personality or intellect might have contributed substantially to the death. (Hence my distinguishing train crashes from car crashes, where the parent's driving shortcomings might be crucial). Divorce is, in one sense, easier - it must surely be due overwhelmingly to features of the personality of one or both parents.
ReplyDeleteIQ: golly, is that evidence of being devoted to political correctness or just of being brain dead? Unless you enter IQ into the analysis, by what magic power can you conclude that it doesn't matter?
Genetics: I'm can't comment on what you've said because I'm not convinced you've said anything. Perhaps rephrasing what you've said into decent English might clarify whether it has any intellectual content.
The statement "Genetics analyses using GWAS are not coming up with solid explanation for heritable traits" is too strong. Success stories do exist.
ReplyDeleteNonetheless, non-positive results from GWAS studies cannot be used to exclude the possibility of a trait being genetically influenced. Classic behavioral genetics models show that intelligence is highly heritable. A recent paper by Plomin et. al. (2013) found that SNP variation accounted for .66 of the twin heritability estimates for cognitive abilities. The reasons for not confiriming all of it might be sample size or that non-additive variance plays a part (or that twin studies slightly overestimate the influence of genetics on cognitive abilities.)
http://www.ncbi.nlm.nih.gov/pubmed/23501967
However, should a child be separated from either parent through death or divorce is certainly not down to inadequate parenting.
ReplyDeleteEchoing dearieme to some extent, I wonder what this can possibly mean. Divorce is a volitional act by the parents, widely perceived (including, I guess by the authors) as being potentially significantly damaging to children. Normally this act is taken in furtherance of the perceived interests of the parents, often quite trivial ones. Parents who make volitional acts seriously damaging to their children but in their own best interests are engaged in bad parenting. By definition, perhaps.
The whole response is very poor.