Counterfactual

The Parallel Lives of Mariko and Caitlyn

In 10 girls, Mariko found its level. 50 years earlier, Caitlyn occupied that same statistical address.

1916–2025

Mariko

peak 1984 2025 192019401960198020002020
Peak year 1984
Peak births 57
Latest count 10
Status Declining
Peak generation Millennial
1968–2025

Caitlyn

peak 1998 2025 192019401960198020002020
Peak year 1998
Peak births 2,937
Latest count 71
Status Endangered
Peak generation Gen Z
Mariko and Caitlyn peaked in the same cultural weather — the Millennial naming world. They are not replacements; they are siblings separated by 50 years, occupying the same statistical address at different addresses in time.