Years ago I had a young lady ask me if I had little brother syndrome. She said I seemed like I was a younger sibling which is actually true as I have an older sister. This was way before I knew what aspergers was. Was just wondering if anybody else has heard of this? Was she possibly referring to aspergers because of childlike qualities I have?
It's possible, but there's a science in to the behavioural traits found in children, depending on if they're an older, middle, or younger child. Of course, it doesn't guarantee your behaviour, but it's a common occurrence in families.
For example, one stereotype is that younger siblings will try to win their parents attention by misbehaving. The psychology behind this is that they are the 'baby' in the family, so are given more leniency, which they're generally well aware of, and so use to their advantage.
On the opposite scale, older siblings generally behave well in order to gain their parents attention. The psychology behind this is that the younger sibling requires more attention, being the youngest, so the eldest child is often shamed for making things harder for the parent, when they should know better, as they're the eldest. This means that by behaving, they gain favour, as the parents are more likely to appreciate it.
Obviously there are hundreds of different factors that can change, or cause these to be completely wrong in various families, but I'm the eldest in my family, and I have one younger sister, and it's definitely true for my family.