These milestones and stages of development are presented according to the ages at which children generally reach them. They are included to help you anticipate and understand your child's behavior at various stages of growth. Remember, each child is unique. Since each child develops on his individual timetable, your child may be ahead of, at, or behind the statistical average. Consult your child’s healthcare professional if he is consistently delayed in reaching milestones or if you’re concerned about other aspects of his development.
Remember: Generally speaking, girls often reach these milestones before boys do. Many behaviors that seem unique to a particular age may repeat at a later age. For you, this means your efforts to teach a behavior to your 3-year-old may have to be repeated when she reaches age 6. But take heart. Because you began teaching her patience when she was 3, it will be easier to manage her impatience when it reemerges at 6, for example.