There are exceptions, of course, and I think supporting socialist policies is one of them: fall of the Soviet Union was a large blow against socialist ideas and changed quite a few minds - ironically, the young people who weren't emotionally affected by it are more likely to support socialism policies, than those who saw their ideas crumble in the country posing as a vanguard of the "socialist revolution". Not to mention that people nowadays are generally quite a bit more educated when it comes to economy, and there are few who hold on to outdated obsolete ideas that apparently don't work.
There probably is some level of change most people experience as they grow older, but I doubt conservatism is what defines it. People just tend to become a bit more pragmatic and mature, they stop looking at the world through glasses of naivety and start becoming more aware of the fact that nothing is absolute. So, I would expect people to actually move towards the middle ground as they grow up - and in societies that are overall more progressive, indeed, that would mean becoming more conservative.
Although there are also those people who, as they grow, only keep building up their echo-chamber, and those, whoever they were in their youth, are only going to move towards a more extreme gradation of the same set of beliefs.