“…In the present study, the mean age at the first sexual intercourse was 20.85 years compared to 17.6-18.0 years in Northern Thailand (Allen et al, 2003;Liu et al, 2006), 13.0-16.2 in America (Zelnik et al, 1983;Coker et al, 1994;De Genna et al, 2011), 14.0-16.8 in Europe (Andersson-Ellstrom et al, 1996Wellings et al, 1996;Edgardh, 2000;Woynarowska et al, 2006;Panatto et al, 2012) and 13.5-17.8 in Africa (Kayembe et al, 2008 ;Dingeta et al, 2012;Doku, 2012;Remes et al, 2012). The delay of first sexual intercourse in the current study may have been influenced by Thai traditional culture, in which early experience with sexual intercourse is considered socially unacceptable (Sridawruang et al, 2010;Supametaporn et al, 2010).…”