The IQ gains of our children have been much more muted. You might say, well, the children haven’t been to university. But children are socialized by the adults that speak around them every day. The question is why are parents less capable of socializing their children into their own vocabulary than they were 50 years ago? I can only imagine that some cultural barrier has built up that insulates the speech of children from the speech of adults.
Could teenage subculture be this barrier?
The word “teenager” didn’t exist in 1950. I was a teenager in 1950, and like everyone else, I wanted to become an adult as quick as possible to get access to money, sex, privacy and a car. Today, teenagers have all of those things without becoming adults. They have enormous purchasing power, and they have developed their own subculture, which is often antagonistic towards their parents. They often have their own speech patterns from texting and slang. I suspect that at least for teenagers a cultural barrier has developed between parent and child. What has happened with younger children, I am still investigating.
In 1950, teenagers could not only understand their parents, but they could also mimic their speech. Today, teenagers can still understand their parents. Their passive vocabularies are good enough. But when it comes to the words they actively use, they are much less capable of adult speak. That is also true of what they would write on an essay.
You have also discovered a trend that you call the “bright tax.” What is this?
The wisdom always was that the brighter you were, the less your mental abilities declined in old age. I found that was an oversimplification. It is true of verbal intelligence. The brighter you are, the more you get a bonus for verbal skills. I call that a “bright bonus.” Your vocabulary declines at a much less steep rate in old age than an ordinary or below average person. But to my amazement I found that for analytic abilities it was just the reverse. There is a “bright tax.” The brighter you are, the quicker after the age of 65 you have a downward curve for your analytic abilities. For a bright person, you go downhill faster than an average person.
This raises an interesting question. Is it something to do with the aging brain, or does it have to do with environment? It could be that a good analytic brain is like a high performance sports car; it just requires more maintenance, and in old age, the body can’t give it. That would be a physiological explanation; the bright brain requires sustenance from the body, which as the body ages is no longer forthcoming. The environmental explanation would be that we use our analytic abilities mainly at work. That means that if a bright person is in a cognitively demanding profession, they are like an athlete; they build up a big exercise advantage over the average person, who has a humdrum job. Then, retirement would be a leveler. That is, if you give up work at 65, you are like an athlete who is retired from competition. You no longer have that exercise advantage of your analytic abilities that work affords. We don’t really know which of these things is true. It could be that they are both true to some degree.
I think this is a great fear for many retirees. What can someone do to stave off this decline?
Retire from your job, but read great literature. Read about the history of science. Try and keep up your problem solving skills. Every bit of evidence shows that the more you use your brain, the fitter it will stay.
The Organization for Economic Co-operation and Development (OECD) found that in countries like Sweden and Switzerland, where people did not retire early, the loss of working memory by the age of 65 was only half as great as in France, where people did retire early.