First, let's sort this out. This is manipulation:
This is not manipulation:
Again, this is manipulation:
The reason that manipulation works is because the end result is something that is mutually beneficial, in most cases. What is offensive about children's manipulation isn't the end result, but the way it was achieved. In the above comics, Calvin's dad isn't going to be sorry that he gave Calvin the pony ride or told him a story, he really will be glad to have spent that time. But the way Calvin achieves it leaves much to be desired. If a child needs to learn to manipulate, then in most cases, some need isn't being met (sometimes, a manipulative parent is the behavioral model instead). Some are more obvious than others--a child manipulating for a toy, for example, may not have a clear motive other than wanting that toy. But that they feel manipulation is the only way to achieve getting that toy is indicative of a communications problem in the home (all relationships require two-way communication--romantic, platonic and familial--to function properly).
An infant is totally incapable of this thought process. What they are capable of is learning to decipher what their body is telling them and attempting to communicate that to their parents (through instinctive motions, signaling, and finally crying). Communication is not manipulation. That is the same as believing a child (who is not yet allowed or able to make their own food) saying "I'm hungry" is manipulative, or a spouse asking "Can you take out the trash, my hands are full?" You can choose to view any inoffensive request as manipulative, but that just creates an adversarial state in that relationship and doesn't make it any more correct.
One of the key ingredients in manipulation is empathy--the ability to understand the feelings of others. This ability is learned (or developed) somewhere between 3-4 years old, typically. Infants are incapable of any thoughts like this. The second key ingredient, cause and effect, isn't even a learned skill until 19-23 months. Sure, they get some basics, like "if I eat, my stomach stops grumbling", but more complex cause and effect like "If I do A, then B happens" (such as a jack-in-the-box) where the relationship of B to A is understood, is a toddler milestone.
Why do we fear manipulation? Because the motives behind manipulation in adults is seldom innocent or in the best interest of the manipulated party. But children are not adults, they do not think like adults, they do not have adult desires and they do not have malicious intent behind attempting to have their wants and needs fulfilled.
Infants, even more so, do not even think like children or toddlers. We are uncertain how infants think, but we are aware of their developmental capabilities. Manipulation--or the adult concept of coercion being used to force another person to do something not in their best interest--is not one of their capabilities.
So when your instincts tell you that your baby is hungry or needs you--your instincts are right. The book (or well-meaning friend/relative/acquaintance/stranger) that told you that your baby is manipulating you is wrong. It really is that black and white. With infants, there is no grey on this subject. They can only communicate to have their needs met. And studies have shown that babies who have their needs consistently met are more secure, independent, trusting, cooperative, empathetic and have a better capacity for dealing with stress as children and adults.