It depends on how frightened a child is of her environment and/or how upset her stomach feels (sometimes as a result of being in stressed/frightened). I found that yelling/scolding at her regarding her condition only makes her more frightened.
My first child was a "cling-on" (i.e. in my baby bjorn baby carrier all day until she was almost 3 and then in my arms until she was 4). I was in tears one night when I was sitting on a rocking chair for 4 hours straight. I couldn't even go the restroom without her around. She had a really bad case of colic and will cry a lot...according to her pediatricians.
When my daughter was able to talk, I found out that she was allegic to dairy products and had a sensory disorder called tactile sensitivities. As a 7 year-old, she's still afraid to go into a dark room by herself. She says that she sees monsters. The more we discount the "monster theory", the more scared she gets. Along with her sensory disorder, she throws a fit if she has a tag on her shirt or seams on her underwear/socks. But, she's a straight A student and doing extremely well physically/socially.
After that experience, I decided to try stepping away from the cries when my second child arrived. I checked to make sure she wasn't hungry, wasn't in pain, wasn't cold/hot, didn't need to be burped, and didn't need to be diapered. Lacking the feel of mobility that I gave her older sister (i.e. the baby bjorn baby carrier), my second child almost became a vegetable and developed some serious gross motor problems. A mommy and me music/movement together class brought her back to life, so we immediately started music therapy to continue to fix her speech and gross motor. She's also seeing a physical therapist. Her fine motor skills have always been great though...from sitting on a chair by herself for so long. She's now doing extremely well socially, but we're still working on her gross motor diabilities.
A healthy balance of being with your child and stepping away is what I would do if I had a third child (assuming the child is not cold/hot, sleepy, or in pain...my oldest daughter was clearly in pain all during her infancy/toddlerhood).
Most importantly, moms model to their kids how to behave. Kids know that they need to cry to get moms attention to feed their inner sense of learning how to behave in this world. They are like sponges taking everything that the mom does, even though the kids can't communicate yet.
Most people would never do this to their child, but children who are left outside in the yard with the dog develops dog behaviors (barking, scratching for fleas, no speech, eating with their face out of a bowl, etc...). They've filmed documentaries on these children. The kids who are older than 6 years of age in these films remain the same into adulthood, but the ones who are discovered in time at around the age of 2 can still be helped out.
So, the first 6 years is really a true test of a mom's patience. Involve your child in your own activities/chores as much as possible, even if she makes a big mess, so she can learn from your own model of patience and learn that helping others/the family can be fun. Those 6 years will go by so fast, but forms the foundation of a child's behavior.