I skimmed through the thread, so apologies if this is restating something that another poster already said.
It's notoriously difficult to measure objective intelligence. We've gotten acceptably proficient at measuring relative intelligence for certain dimensions of that attribute among a given population, but even those measurements fail when placed side by side with another study done in a wildly different population, and all they are is comparative rankings of specific cognitive attributes, not actual rigorous measurements of some universally accepted definition of 'intelligence'.
In other words, I mistrust any study like this as anything but (potentially thought-provoking) speculation, because nobody can actually measure the thing they are talking about.
EDIT: Also, I find it interesting that people often assume that, once an attribute stops being selected for, it somehow rapidly falls into decay. Genetic drift tends to lead to the fixation of traits when selection isn't pulling too hard in one direction or the other, especially in large populations. To say it another way, if your not pushing up on it or pulling down, it tends to stay the same.
Sure you could argue that intelligent brains are expensive, but they are also very useful, and I don't think anyone is arguing that there is no competitive advantage at all to being very smart. So yeah, I've always been suspicious of the old argument that humanity is getting dumber, and this article doesn't change my mind.
It's notoriously difficult to measure objective intelligence. We've gotten acceptably proficient at measuring relative intelligence for certain dimensions of that attribute among a given population, but even those measurements fail when placed side by side with another study done in a wildly different population, and all they are is comparative rankings of specific cognitive attributes, not actual rigorous measurements of some universally accepted definition of 'intelligence'.
In other words, I mistrust any study like this as anything but (potentially thought-provoking) speculation, because nobody can actually measure the thing they are talking about.
EDIT: Also, I find it interesting that people often assume that, once an attribute stops being selected for, it somehow rapidly falls into decay. Genetic drift tends to lead to the fixation of traits when selection isn't pulling too hard in one direction or the other, especially in large populations. To say it another way, if your not pushing up on it or pulling down, it tends to stay the same.
Sure you could argue that intelligent brains are expensive, but they are also very useful, and I don't think anyone is arguing that there is no competitive advantage at all to being very smart. So yeah, I've always been suspicious of the old argument that humanity is getting dumber, and this article doesn't change my mind.