About 50 years ago, child psychiatrists Stella Chess and AIexander Thomas claimed that infants show behavioral characteristics at about four weeks after birth that indicate the child’s future personality. “At one month, behavior starts to become discernible, said Chess. The two researchers believed that such behavior could also be used to predict serious problems that could develop later in life.
  At the time, their theories were widely rejected. Most psychologists branded them determinists, arguing instead that the minds of infants were blank slates that parents and others could write on. Now, however, Chess and Thomas are receiving increasing attention from behavioral scientists trying to apply their techniques when dealing with so-called problem children. Researchers have found that about 60% of all infants have easygoing temperaments. The remaining 40% display such problems as severe moodiness or defiance that mark them as difficult infants.
  By identifying these characteristics early on, parents and professionals have a better chance of eliminating certain problems that could lead to attention-deficit hyperactivity disorder (ADHD) or depression in later years. Without such intervention, 80% of infants diagnosed as difficult, mostly boys, become overly rebellious and hyper-excitable. They are also at greater risk of developing ADHD.
　The other 20%, mostly girls, become withdrawn and run the risk of developing depression, phobias, or compulsions. According to pediatrics professor Dr. Lawrence Diller, using parenting techniques tailored to a child's personality can improve the child's behavior dramatically, making life easier not just for the child but also for the parents.
  Not all difficult babies inevitably become difficult children or adults. Indeed, if parents follow Diller's advice, they stand a good chance of turning their problem infants around.