My DD who's 8 years old has been conscious about her privacy for two years now and doesn't let anyone see her naked. On the other hand, my nephews who are 9 and 7 years old are still not bothered about their privacy. They still shower or use the toilet with the door wide open, change clothes in front of us without caring etc. My DS, like my nephews, also isn't bothered about privacy yet, but he's still only 5.
What age do boys become self-conscious about privacy/nudity? Does it happen later for boys compared to girls? Or are my nephews just exceptions?