More on what we "inherit"

Apropos of yesterday's post about irresponsible journalism. Here's what happens when you misuse the term "inherit." In the World Science entry:

A study has led reÂsearchÂers to specÂuÂlate that career sucÂcess may be partÂly geÂneÂtic.

The supÂpoÂsiÂtion rests in partÂiÂcuÂlar on two new findÂings, the inÂvesÂtiÂgaÂtors said: that willÂingÂness both to take risks and to trust felÂlow huÂmans seem inÂherÂitÂed. Since asÂtute judgÂment in both areÂnas are cruÂcial to sucÂcess in busiÂness and a range of othÂer fields, that itÂself might be heÂredÂiÂtary, they reaÂsoned.

Now, here's what the research article actually says:

These genetic and social influences may act in concert, and possibly interact. To have a hope of distinguishing genetic transmission from transmission through socialization would require, at the very least, observing children at much younger age, or observing a large sub-sample of children who were not raised by their biological parents, or observing attitudes of a large sample of fraternal and identical twins. Thus we leave this issue for future research. We do suspect, however, that genetics is not the sole transmission mechanism, based on our results on the impact of parental characteristics and family structure. [emphasis mine]

There seems a fascination in the media with the idea of genetic "inheritance," when even researchers advocating some level of genetic influence also acknowledge important non-genetic factors. Here are some other recent examples:

• From Mind Hacks: "intelligence was positively related both to head size at birth, and to head growth during childhood."
• From UPI: "Genetic risk for violent behavior?" (This article later qualifies the claim implied by its headline: "While the MAOA-L gene can be a predictor, it is important to recognize that the genes influencing behavior have a very small effect. Even combined with stressful environments, there is no perfect indication that one will become antisocial.")

As Coturnix pointed out in his comment on yesterday's post, the mechanisms of transferring traits from one generation to another are complex, and clearly they are often oversimplified by the media as "inherited" or "genetic." It's probably not practical for media outlets to give a mini genetics lesson every time they post an item about these topics, but it might help if they could be somewhat more consistent in their use of terminology, and a little less singlemindedly focused on the genetic component.