Physical and emotional, eh? I'm going to explore a different take on this question and talk a bit about the parental choice of safety vs. exploration.
All playgrounds are a physical risk. Does that mean a child shouldn't play on them?
The degree to which a parent decides upon safety over exploration can absolutely affect the physical and emotional development of their child. Now, I'm not saying that all children should be explorers either. For some, it is not in their nature. Some are more homebodies, happy with sticking to the everyday. Some are also accident-prone, and those should be kept a close watch on. The problem arises when a parent is overly safety-conscious while his/her adventurous child wants to explore.
Very simply, ... I have two adventurous children, ... so I nervously let my children climb trees, swing on three-story tall rope swings, and tube in the river. These are not the safest activities to do with my kids, I will admit. However, for an adventurous child, they need to be able to explore them with a parent who does know something about safety.
Anyone who trends toward the adventurous side will have their share of bumps and bruises. Yes, I've had a child fall off the swing more than once. Yes, I have mistakenly tubed with the kids in a hailstorm. (Haven't had one fall out of a tree, though, ... knock on wood.) Even after all of these departures from safety have happened, my thought was always the same, "I hope this doesn't cause my child not to want to explore!" Luckily, the exploratory nature of my children remains the same no matter what. (And would I struggle if one of my children were more on the hesitant and safety-conscious side, just as many parents struggle with the opposite? You bet!)
Therefore, it's simply important to take into account the nature of the child in regards to exploration and foster them according to his/her nature, ... NOT according to the parent's nature.
One thing that is often not taken into account is the attitude of the parent(s) toward the child. Children only thrive when they are respected and admired from their earliest ages onward. Very often--at least in America--children are subject to what historian Page Smith may have labelled "social psychosis" and made the brunt of sarcasm, irony, ridicule, taunts, witticisms that may perhaps be all well and good when exchanged between intelligent adults but which are not beneficial to the nutruance of the child.
This is a huge topic because there are so many factors involved and because different children respond in different ways, even if faced with the same condition. Parenting style builds a basis of self-concept and security in the world; parenting responsibly insures that basic physical needs such as nutrition, shelter, and medical concerns are addressed. Reflecting the idea that "it takes a village to raise a child," others outside the immediate family help a child to understand what it means to be recognized and needed, to fulfill a role within the group, and to become part of something bigger than oneself.
Changing any of the above scenarios will impact the physical, emotional and psychological development of any individual.
You may be interested in following the line of the maternal influence upon a child. It is a horrifyingly curious fact that the majority of serial killers had abusive and/or cold mothers. Many psychologists are convinced that the maternal influence has a tremendous impact upon self-confidence, security, and so many other factors.
I love the idea of questioning what will effect a child emotionally and physically as they grow up. I do not think that enough people look at the imprinting years serious enough.
I think that things that will harm a child emotionally are: an unstable family dynamic, lack of emotion from parents/care giver/siblings; feelings of disappointment (telling a child that they are bad over their behavior is bad; and failing to attach to a parent/care giver.
Physical harm: I think these are pretty known- abuse, lack of good diet, smoking/drugs in home.
I am sure there are a million other things that the field of psychology or child development would add, but these are the things I thought were of the most importance.
Clearly getting enough sleep and eating nutritional foods is the foundation for strong, healthy children--adults, too, for that matter. Without these two things, everything else is worse--or at least seems worse.
It is interesting that some psychologists argue that the first five years of a child's life is where the blueprint of the rest of their life is laid down. This is something that should make every parent sit up and take careful consideration of the amount of time they spend interacting meaningfully (rather than putting them in front of the TV) with their children. Certainly, parental time is something I would definitely say would be most important.
The conditions of the neighborhood in which a child grows up are a major factor in his emotional and physical life. If a child grows up in a violent neighborhood, he is more likely to either embrace violence as a lifestyle or be constantly afraid. Either has an effect on his health. Children cannot be healthy when they live in unhealthy neighborhoods.
I would argue that the major factor that affects the emotional life of a child is the amount and quality of time that their parents are able to spend with them. I think that children in our American society today expect that their parents will spend time with them and show them love and affection. If this happens, the children will be likely to be emotionally stable. This is likely to help them physically as well.
Children are as individual as adults in terms of how they respond to the external world; indeed, there has been a great deal of debate over the years regarding which impacts a person's development more, nature or nurture. There are many things that impact a person's development, but as an educator, I have seen many of the same things appear and reappear over the years, affecting the academic achievement of children. A few of these include divorce of the parents, verbal, sexual and/or physical abuse at home, bullying, unidentified learning disabilities, attention deficit and/or hyperactivity disorders, and large class sizes which decrease the amount of individual attention a struggling student might receive.
The most obvious lies in the environment of the child. Since children learn by observing their surroundings, they are easily influenced by others, especially their parents, friends and teachers.