Demographers differ on just what ages they include in this next generation. Some include those born since 1980; others start with 1982 and go to about 2000. Most researchers have focused on the ââ?¬Å?first-waveââ?¬Â millennials ââ?¬â? those roughly ages 16 to 25. Although there’s no one set of traits that everyone shares, research has suggested some commonalities in areas ranging from home life and education to workplace behavior and leisure-time interests.