Matching Pairs Developmental MilestonesOnline version When do you believe these behaviors first appear in a young person's life? by ISRC Widener 1 Experience an erection or vaginal lubrication 2 Become aware of how their body functions 3 Have an understanding of their own sexual orientation 4 Feel curious about bodies 5 Begin to recognize traditional male and female gender roles 6 May engage in same-gender sexual exploration 7 Value privacy highly 8 Touch their genitals for pleasure 4-5 years old 0-3 years old 0-3 years old 13-17 years old 4-5 years old 4-5 years old 6-8 years old 9-12 years old