You should know better than to interpret a latitudinal study this way. They showed that the relationship between intelligence and personality changes with age. But they didn't show whether it was intelligence or personality that changed. You need a longitudinal study to answer that. Yes, yes, I know. Longitudinal studies are hard. That is why nobody does them. But that doesn't excuse your jumping on the most sensationalistic answer available.

Allow me to explain for those who don't find that statement self-explanatory.

A latitudinal study is when you take people of different ages, look at them, and try to draw correlations. A longitudinal study is when you take a group of people, study them, then follow them through time and keep on following up on them over time. Latitudinal studies are a lot easier and faster to do. The problem is that you don't know - in fact you can't know - which young people should correspond with which old people. That kind of question can only really be answered with longitudinal studies.

To summarize the research, they looked at a lot of people and found that in different age groups the relationship between personality and intelligence is different. And they found that while dewey-eyed idealists were smart youngsters, the smartest people are crotchety old folks.

My point is essentially that you don't know whether being crotchety is an effect of having been smart for a lifetime in a world full of (relatively) dumb people, or whether crotchety folks start off slow and then keep on improving throughout life.

If I had to guess, I'd say that personality changes and intelligence does not. So all of the amiable, agreeable guys & gals, listen up. Listen to the old man (me). You are doomed to cynicism in your old age, but don't rush to get there. You have a lot of disillusionment ahead of you, and you want to savour every heartbreak as your naivete is shattered.