I just discovered your blog and plan to follow it. I'm a 26 year old only child with a keen interest in psychology (though my current MA is in poli sci).
I'd like to add that the article does not make a clear distinction between imaginary friends of the "invisible" sort; an unseen child of a similar age, and an imaginary friend that is an animal or doll. Is there a distinction? I never had invisible friends, but had stuffed animals (one squirrel in particular) with elaborate personalities and communication skills. This never occurred to me to be a product of being an only child, but seemed quite normal.

I do see some problems that reoccur with other only children and in my case. One of those is that mothers tend to treat their only daughters as best friends and peers. This doesn't seem to affect socialization but does affect the daughter's view of herself even into adulthood, I think for the worse. Do you find this? Is this an explored area?

I would also like to ask about stereotypes, for instance, the idea that we are selfish. Because I never had competition for my belongings, I didn't feel defensive about them and often gave items away or wasn't bothered to let others play with them as they wished. I find this among other only children as well. This seems a logical inference and I can't imagine why the stereotype exists.

Great blog.

J & J asked about the difference between a stuffed animal companion and an invisible one.

There is a distinction between an invisible imaginary friend and a stuffed animal or doll friend. In Taylor’s study, if a child could provide psychological details about the doll or stuffed animal such as “She is mean to me” or “He tells lies,” the object was considered an imaginary friend. Stephanie Carlson, co-author of the study, noted that of the children studied, 52 percent of the preschoolers’ imaginary companions were based on stuffed animals and other props; 67 percent of school-age children’s “friends” could not be seen. Among school-age children, 57 percent of the companions were human; 41 percent, animals.

My older daughter (now 5) had an imaginary friend, Puppy, before our younger daughter (now 2) was born. For the past several months, our younger daughter has been telling us stories about Puppy too. I have never heard of siblings sharing the same imaginary friend. Is this common?

Could be your older daughter discussed Puppy with her younger sister who latched on to the name. It would be interesting to know if the sisters tell similar stories about Puppy. Siblings sharing the same imaginary friend is not a common scenario. It may be among twins, but I haven't seen any studies to support twin sharing of an imaginary companion.

My older brother and I shared the same imaginary friend, an indian brave, named Jeremy. We had been living out in the country, in Michigan, for about two years and adopted a favorite oak tree in the tree line of our property. One day, we started including Jeremy in our playtime.

He was tall, and never spoke, he was just assisted us in whenever we had to use our "muskets" to hold off outlaws. He was the only one we ever had.

I had an imaginary friend as a young child which was a donkey. My mother was told by some friends that they read that this is a sign of some sort of demonic entity. I'm twenty six now and do not remeber this friend but my mom brings it up alot and I find it to be a total witch hunt. So I would like to know if there is any truth to this, could it of been demonic. From reading several sites on the subject I have found no such proof on it.

Imaginary friends take many forms--human, animal,objects. I've seen no literature to suggest that fantasy friends are demons in whatever form they "appear." Rest assured, your donkey friend was undoubtedly harmless. I suspect his merely being "present" scared your mother and she was willing to accept whatever explanation was offered.

Today my daughter (10) told me she has had an imaginary friend who has been a bully to her for the last year. Tonight she, the bully, was mean to her again which ended with a broken towel bar in the bathroom. Through torrents of tears, she finally told me that "Stacy" is mean to her. My daughter is an only child, however, when our nephew was staying with us (he's 2) for two months she said "Stacy" didn't bother her at all. I am at a loss. I have never heard of an imaginary bully, is this an early sign of something worse?

My 5yr old son uses his imaginary "brother" to share replays of any event. Usually he shares my daily goings-on, but does bring up the loss of my son's mother. My son was present for the ambulance arrival at the house and knows she passed away at the hospital.

But, my son tends to make up stories for seemingly pure entertainment. Luckily he has a "brother" to act the main part.

they call it then just religion. In fact the WHO forgot to take action against this so that for the mental disease 'religion' is no ICD 10 number.

Wow, what an interesting topic. I too had an imaginary friend named Shelly Bo Peep. I was not an only child, but rather, a middle sort with two older siblings and one younger sibling. Shelly came into my life when I was around 5 years old, roughly the time my mother remarried. In addition to being in a blended family, it turned out our new step-father was an alcoholic with a temper. It was during this difficult time that I created Shelly to help cope with the stress brought on by my parental dysfunction. Shelly stayed with me throughout this period of my life, until my mother divorced her husband and we moved away. Shortly thereafter while riding in the car with my mom we crossed a busy intersection and Shelly (who instead of being in the car was walking along the side of the road) was hit by a car. It was not a death scene from a movie, she just disappeared and never came back. I think that because my life had returned to a normal state my need for Shelly's companionship dissolved. Perhaps her being hit by a car enforced a permanent departure, therefore signaling an emotional green light for me to positively move foward in my development. Any ideas or comments on this style of coping?