What are other possible explanations why babies cry?

Crying are said to biologically rid the body of unwanted stress. A zinc-deficient baby can cry inconsolably and be very difficult to soothe. Van De Rijt and Plooij identified crying periods which all babies go through: 5 weeks, 8 weeks, 12 weeks, 19 weeks, 26 weeks, 37 weeks, 46 weeks, 55 weeks, 64 weeks and 75 weeks. Harvey Karp advocates that by trying to recreate the womb, it is possible to alleviate some, if not all of a baby’s crying. Of course, there are also reasons such as when they are sick or teething or also possibly bored.