Cognitive development refers to how your child’s mind is working and his process of learning. At two years old, your child’s brain grows so fast that 250,000 nerve cells are added every minute. Your child’s brain continues to grow after birth; by two years of age, your child’s brain will be about 80% of the size of an adult brain. In this year, your child’s learning process is becoming more thoughtful and is greatly inf luenced by his environment. Your child is naturally curious and inquisitive and through his play investigates to make sense of the world around him.