Children's Age-by-Age Guide: 12 to 18 Months

Emotional Milestones

Your one-year-old will now really show how she feels -- she'll smile when you praise her and cry when you scold her. She may begin to throw tantrums when she gets angry. At this stage of emotional development, she doesn't follow rules and warnings very well yet.

Smart Strategy:

At this age, you need to apply discipline swiftly yet gently to help her link her behavior to its consequences. Consistency is key -- "no" should always be "no" when it comes to safety limits you have set. Praise her efforts to cooperate with you and try not to hold grudges against her when she balks, which she will at times.

Now is when you can really see your baby's mental ability growing. He'll recognize his name and may point to a familiar body part like his nose or toes when you ask him. He realizes that everyday objects like telephones and brushes have unique functions, and knows where certain objects belong. He even can tell when a book is upside down!

Smart Strategy:

You can further his cognitive development by matching words with objects and actions; this will reinforce connections. For instance, each time you see a dog, say "doggie." When you say it's time for dinner, let him see you cooking; when its time for bath, show him how you run the water to fill the tub.

• 6 to 18 months -- Third dose of Hepatitis B (Hep B), if he hasn't already had it.
• 12 to 15 months -- Pneumococcal Conjugate (PCV)
• 12 to 15 months -- Measles, Mumps, Rubella (MMR)
• 12 to 15 months -- H. influenzae type b (Hib) Booster
• 12 to 18 months -- Varicella (Chicken pox), if he hasn't had Chicken pox
• 15 to 18 months -- Diphtheria, Tetanus, Pertussis (DTap)