Before I had a kid, I hadn't really spent a lot of time with young children and their parents. None of my close friends had children. In my extended family, only my in-laws had small children. (Of course now that I have a baby tons of people are pregnant or planning to be soon, which is funny.)
So I didn't really have any idea of how most parents actually parented, not having seen them in action except in passing (and a one-time incident doesn't tell you much). My in-laws have rather a disastrous parenting style (their two boys are exceptionally ill-behaved and will only behave when sedated with constant video watching; the time we went to a restaurant and the portable TV failed was certainly memorable), but since I had a sample size of one I couldn't really draw any conclusions.
Now I spend a lot of time in groups of (mostly) mothers with their children, and thus have had the opportunity to observe parenting in action. What's fascinating to me is that: 1. the skill level of parents varies wildly and 2. a LOT of people are not any good at parenting (like maybe 25% of all parents).
I assumed that most parents would be pretty similar in skill level, assuming that their experience (as in, how old their children were and how many they had) was similar. After all, most parenting tasks are fairly simple (keep the baby clean, fed, rested and out of danger; don't beat or scream at them; give them hugs and intermittent attention), and can be done successfully by illiterate peasants. But no.
Some (most, really) parents are good: calm, patient, and kind the vast majority of the time (of course no one is perfect). It's easy for them to explain their children's behavior and understand them, because they can read their subtle cues, even though usually what's going on is not obvious to anyone else. In fact, the level of psychological insight and sensitivity in the really great parents is amazing and impressive. The good parents handle their children with confidence and yet careful gentleness.
Other parents, however, seem really tone-deaf to their children's needs/wants/signals. They never pick up on their cues (often even when they are obvious to everyone else) and seem confused by their children's behavior and emotions. Sometimes it seems like the parent just met the child, because the easy emotional familiarity you would expect is just missing. They often seem awkward or jerky with the child, or too rough, or too passive.
The weird thing is, the behavior of the babies in each case is really pretty similar; they have the same desires, expressed in very stereotyped ways (crying, eye rubbing, gnawing on things, whining for attention, etc.). It's the reaction of the PARENT that's different. (Of course, as the children get older, maybe 4 or 5, the ones with the tone-deaf parents do tend to behave quite differently).
If this was just a very few parents, then I would just conclude that the unskilled ones had horribly abusive childhoods or mental problems (untreated depression maybe?). But a large minority of parents are this way, and seem normal in everyday conversation. None of them are blatantly abusive or neglectful. However, the effect of their inability to be sensitive to and in tune with their children is terribly devastating, causing obvious emotional pain even to their small babies.
I don't think the parents mean to do this; it seems more likely that they have no idea to do what comes naturally to most parents (sensitively and affectionately responding to their children). Probably their own parents were the same way. But it's sad.
It's facts like these that make me think extensive parenting classes (with supplementary psychological counseling, perhaps?) should be mandatory.