Siblings: Birth order and personality

They are characterized by the following features:

Mature for their age
Extreme perfectionists
Hyper-responsible
Diligent
Leaders
They feel more comfortable with adults than with other children
Only children, growing up surrounded by adults, are more verbal and generally more mature. This can allow them to develop their intellect more fully, since having spent so much time alone fosters skills like resourcefulness and creativity. In many ways, only children are very similar to firstborns, but they take these qualities to extremes. They are natural leaders and tend to be very perfectionistic, conservative, and organized. They are difficult to manage. They are often relentless, very demanding, and hate to admit they are wrong, and they generally do not take criticism well.