Reddit reviews The Scientist in the Crib: What Early Learning Tells Us About the Mind

The Scientist in the Crib. It's not about parenting exactly, but it will give you an informed perspective on child development.

I can't answer the question definitively, but an interesting phenomenon that I've observed as a teacher is how teaching infants sign language allows them to exhibit their cognition and thought process. I teach in a Montessori infant classroom and I've taught babies (under 18 months) signs that I then see them use in different but totally appropriate ways. For example: we use the sign "outside" to mean literally out-of-doors in the fresh air. But we have kids who then use the same sign to mean "out of the classroom", "out of this area", "come to this side of the fence," etc. They are showing that they understand this concept of "i am here and I want to be elsewhere". They don't have the verbal/physical words, but the neural pathways are certainly there, and every time someone uses that sign or says "outside" that pathway is being reinforced. Obviously, I don't know for sure, but I would imagine that since these children are signing in response to heard words, if you could see a brain scan you'd see areas lighting up for thinking of the sound of words, and also motor skills for thinking about the movement of signing.
Now I want to see if anyone's done this kind of study, and if not, why not?! Off I scuttle to do some research....

Edit: a really terrific resource for understanding infant cognition is Alison Gopnik. She's a cogsci researcher out of UC Berkeley and she's written the following:

[The Scientist in the Crib](The Scientist in the Crib: What Early Learning Tells Us About the Mind https://www.amazon.com/dp/0688177883/ref=cm_sw_r_cp_api_bboSybE1V7Q9G)

[The Philosophical Baby](The Philosophical Baby: What Children's Minds Tell Us About Truth, Love, and the Meaning of Life https://www.amazon.com/dp/0312429843/ref=cm_sw_r_cp_api_QboSybDSGGJZQ)

I can't speak for [her new book](The Gardener and the Carpenter: What the New Science of Child Development Tells Us About the Relationship Between Parents and Children https://www.amazon.com/dp/0374229708/ref=cm_sw_r_cp_api_udoSybM1SFBSC) but I can tell you that the first two completely changed the way I view babies. They really are amazing little people with astounding cognitive abilities from birth!

This was a good book:

http://www.amazon.com/Scientist-Crib-Early-Learning-Tells/dp/0688177883

Your question is very broad. Most parents don't think about the bulk of how they raise their kids in an especially rigorous way. They do things their parents did that they think were probably good ideas, and (usually) try to avoid doing things they think were probably bad ones. The problem is that most people don't try to use anything beyond anecdotes, preference, "folk wisdom", and convenience to inform their parenting practice.

Other people try to be more deliberate about it and approach parenting sort of like how teachers approach teaching. I fall more into this camp. It's important to me to have a theoretical foundation to inform my parenting choices, and as much as I can, I try to back up that theory with some kind of research-based evidence. Despite this, boolean_sleedgehammer is still right that no one knows exactly what they're doing.

I recommend developmental psychology books like this one.

While not specifically for pregnancy, I found these books incredibly helpful. They're written by neuroscience researchers at the University of Washington and my daughter and I ended up being selected as participants in some of their student's studies! The second book heavily influenced my parenting style (or reinforced what I was doing instinctively) and either I got lucky with a good kid or they're quite effective.

What's Going on In There: How the Brain and Mind Develop in the First 5 Years of Life

and

The Scientist in the Crib