Tuesday, 23 August 2016

A picture from our forthcoming article in Intelligence

Here is a single bar chart from our forthcoming article in the journal Intelligence. (I've edited it a bit to have nicer colours.)

The bar charts represent individuals' Polygenic Risk Score for educational attainment. That is, each individual gets a score predicting when they will finish education. Don't worry about the details of how this is done: the point is that it combines the effects of many different genes, and it is purely derived from DNA. Give me a cheek swab with your DNA, or your child's and I will calculate your score. Bars 1 to 5 represent the bottom 20% of our sample on this score, then the next 20% and so on up to the top 20% on the right. The bar colours show the proportion of each group that went to university, got A levels (i.e. the age 18 exam in the UK), got GCSEs (the age 16 exam) or left without any qualifications.

This isn't actually what our article is about – our article is on assortative mating between spouses on this score.

The picture just shows that as of 2016, you can predict someone's education fairly well from their DNA. For example, only 1 in 5 of the bottom 20% group go to university, while about half of the top 20% do so.

It used to be that, while genes could significantly predict social outcomes, the amount of variation they actually explained was very small – it was statistically significant but substantively irrelevant. As you can see, that is not really true any longer, and it is likely to get less true as more large-N studies produce more accurate predictions.