I am the quintessential only child. I am an only child, and on my mother's side was the only grandchild and only great-grandchild for 18 years. As my parents seperated when I was very young and I was then raised by my mother with very little association with my father, I did not and do not now know my paternal cousins.
Certainly there are distinct disadvantages to being an only. It has taken me a long time to realize that people tease others jokingly when they like them as often as they tease others cruelly when they don't. My chosen profession as a copy editor points to my extreme perfectionistic tendencies. The white-hot attention paid to me by my mother, grandparents and great-grandparents was as much of a gift as it was a curse and I fight the tendency to run back to the comfort of my "by myself "safe haven when the slightest issue upsets me. Most uncomfortable is the spector of having very little familial support as my mother and I age. When my father died, I was profoundly affecetd by the realization that one day I might be alone in the world as everyone that knew my intimate childhood history would be gone. That having been said, I don't regret being what is now called a singleton.
I am first and foremost a live-and-let-live person. I attribute this to never having formed hard and fast rules of social engagement (war) hard-wired into my brain by daily sibling interaction. I know like few others that people's personal traits are what makes them who they are as opposed to tools to use against them. It does not matter to me if one is different because everyone is different from me in a most basic way. So I take others as I find them judging not them personally but their behavior as acceptable or unacceptable for me to engage in and I leave it at that. Unlike many who I have seen destroyed by the inability to love from afar siblings who are cancerous, I know that I alone am ultimately responsible to care for myself so I have no problem or lingering guilt when I let go of a toxic relationship. While I had to learn to stand up for myself (no sibling battles over toys and such to teach me), I do not carry old wounds of self-doubt forged by thoughts that Mom liked my sibling best. My self esteem is intact. Having had uninterrupted time to consider the universe and my place in it, I can truly say I know who I am and what is important to me.
In terms of conflict management, I carry no lingering need from childhood to get what is due me because I had everything that I needed and a good bit of what I wanted as a child. Therefore, I can concede when need be without feeling like I am being duped, overlooked or taken advantage of once again. As I think many conflicts are actually old fights being fought over and over again, the fact that most of mine are new and colored by maturity means that "winning" an argument is not as important to me as getting to the root cause of the issue.
Finally, and perhaps most importantly, I am not afraid to be alone because I like me. While I do like interacting with others, I revel in and need the solitude of "me" time. I do not feel guilty when I take advantage of a rainy day to read a book or daydream.