Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Mean age of first intercourse (95% CI) for sexually experienced twins whose co-twins have abstained from sexual intercourse (Discordant pairs) and for twins whose co-twins have initiated sexual activity (Concordant pairs).
| MZ Twins | Same-sex DZ Twins | Opposite-sex DZ Twins | |
|---|---|---|---|
| Discordant | 19.88 (19.25–20.51) | 19.07 (18.52–19.62) | 17.97 (17.42–18.51) |
| Concordant | 17.28 (17.12–17.44) | 17.38 (17.24–17.52) | 17.48 (17.34–17.62) |
