Around 18 months of age, children will begin showing more independence, such as insisting "I do it myself." It's important to understand that your child sees herself as the centre of the universe - not in a selfish way, but in a self-centered way. In other words, she believes everyone is experiencing what she is experiencing; what she knows, everyone knows. This happens because, at this age, seeing herself as a separate being can be a bit scary and confusing.
You also may notice that your child's moods swing rapidly - between being proud and bold, to whiny and scared, or even to being angry and throwing tantrums. This, too, is part of your child's struggle for independence.
It's around this time that children start experiencing the new emotions of pride and shame. Dealing with these emotions can be very tricky, so try to be careful not to make your child feel ashamed of his efforts to do something, even if the outcome isn't exactly what you expected. For example, feeding himself is usually pretty messy at this age. But praise his efforts and soon the neatness will come.
Socially, children will enjoy playing near other children, but not necessarily with them. At this stage, your child isn't ready for you to teach her to take turns. That comes a little later. In the meantime, provide opportunities to have other children around, but be ready to gently intervene (many times) when her lack of sharing skills needs shaping.
Remember, each child is unique. Not all children develop at the same rate in each area, such as movement, communication and relating to others, so this information is meant only as a general guide. If you have concerns about your child's development, you should consult your child's doctor.