Elliot suggested in comments below that while children who get held a lot may be happier, it might not be the holding that helps them. Instead, it may be because their parents care, or are not distant.
Is a child of loving parents going to be happy? There is no reason why that should be the case. You can love someone and care for them without respecting their wishes. There are points in many children's lives when this is all too clear: the time when children begin to be aware of being manipulated and coerced and forced to do things against their will, and learn how to buckle under it, is often known as "the terrible twos"; the moment when children finally have the physical strength together with mental frustration which leads them to reject this coercion is known as "teenage rebellion". The fact that western babies are expected to spend a large amount of their time crying suggests to me that the first months, when they are becoming accustomed to not being responded to, is another key moment.
Caring is not sufficient. A caring parent of the 1950s or 1960s, wanting to give their child the best possible start in life and reading all of the most highly recommended parenting manuals will have:
- Not fed the baby more often than every four hours, and only for ten minutes on each breast.
- Moved onto solid foods (and OFF breastmilk entirely) when the child was four months old, on the advice of the health visitor.
- Never brought the baby into bed for fear of smothering them. Sitting up to feed at night will have made the mother exhausted, for months on end. One of the most common questions asked of new parents, with a smirk, is still "how are you sleeping?"
- Worried about spoiling their child by holding it too much.
Things have changed a bit, but new mothers still worry about whether their milk is "good enough" or whether "baby likes it", about whether it is time to start pureeing vats of simple solid food for a baby with no teeth, about whether they would smother their baby by bringing it into bed and whether, once in, a child would EVER be prepared to sleep alone, about whether they will become a slave to their child by trying to help hir when se cries.
Caring has to be combined with responding to the baby's wishes to keep everyone comfortable. Most babies want to be in physical contact with their primary carers for greater periods of time than mainstream western society expects, and it takes great self-confidence to do that against the advice of most books and health care professionals.
It occurs to me that parents are more likely to have self-confidence with second and subsequent children... perhaps non-first-born children tend to be more relaxed... [bah - cod psychology]