| Clue | Source | Date |
|---|---|---|
| Expected life-stage behavior | Newsday | 07 May 2026 |
| Expected life-stage behavior | Newsday | 15 Oct 2020 |
| Developmental point of reference | Wall Street Journal | 05 Dec 2019 |
| Benchmark figure given how old a person is | New York Times | 12 Dec 2018 |
| Benchmark figure given how old a person is | ||
| 18 for graduating high school, e.g | LA Times Daily | 09 May 2015 |
| 18 for graduating high school, e.g. | ||
| Average performance for one's years: 2 wds. |