That is false. 18-34 is not a discreet group. Those that are 18(as a group) don't have the same goals and drives that those who are 30+(as a group) have. Hell, they probably aren't even the same as those who are 25-26. What people want changes as they age, which is why so many young marriages end in divorce.
Would that be older people as in 35-40? 41-45? 46-50? 51-55? And so on, because as I point out above, groups change over time. Not as drastically at these age categories as 18-24, 25-30, and 31-35, but still changed.