Infants communicate through crying. It is a normal, developmental stage that all infants go through, especially in the first four to five months of life. The crying typically increases at around two weeks of age, peaks at two to three months and declines by five months. Some infants cry as long as five hours a day or more while others cry for only 20 minutes or less each day. This is still normal.
Crying, especially inconsolable crying, is the most common trigger for shaking and physical abuse. Research has shown that all normal infants have inconsolable crying in the first few months. Some have much more than others, with infants in approximately the top 20% considered to experience colic. Parents can reduce most crying bouts but when it comes to inconsolable crying, there is little they can do to reduce it which can be frustrating.