As a child I was sometimes unfairly bullied by children and adults (who should've known better) about my only child status. Not that this happens to all only children, it's just that I was brought up in a unique type of close knit community which I think made attitudes worse. Anyway as an adult I can name about 6 or so people who are really struggling to adjust with feelings of loneliness, etc awareness of their poor social skills and not surprisingly they're also not doing well professionally. ALL of these people have siblings! The vast majority of only children I know are doing quite well - they may not be exactly Managing directors of huge multinationals or anything like that - but doing well both professionally and in relationships. So despite the negativity I received in childhood about being an 'only' my adult experience of people has proved very different!