"Consider birthdays. "You measure how much a person actually cares by which form of communication they use," Samantha told me. "Acquaintances will write on my [Facebook] wall. A friend will text me. A best friend will call." When Samantha's best friend texted her late in the day on her birthday, she was hurt. "It kind of makes you feel like an afterthought." With girls constantly connected, they may judge and dissect even the timing of a message."