Generally speaking, young people should take higher risks when investing if the goal is retirement.
Higher risk means higher returns, assuming all goes right. If things don’t go right, young people have a lot more time to make up any losses.
But retirement isn’t always the goal. For example, you might be saving for your child’s education. And while you might still consider yourself pretty young, you will want to take fewer risks with that money as your child enters high school.
Whatever you’re investing for, you will generally want to reduce the amount of risk in your investments to protect what’s already accumulated as you get closer to your goal.