Johnson et al. have published an interesting article in the August 2011 edition of The Canadian Journal of Psychiatry (pp. 447-456) in which they describe a nice longitudinal study of 669 families, correlating parenting behaviour with future personality traits in the offspring.
To some degree, studies of this type might seem to be re-examinations of the obvious -- that is, children of friendly, gentle, stable, involved parents are more likely to be healthy and stable themselves. The thing is, much of this effect is arguably due to heredity rather than parenting. The genetic factors which influence temperament, mood, personality, etc. are likely to be present in both parents and children--the impact of parenting behaviours themselves are therefore likely to be overestimated.
A good method to tease out these factors would be to study families with adopted children, provided there is good data about psychological characteristics of the birth parents. In general studies of this sort have led to the surprising conclusion that genetic factors are quite a bit higher than expected, and parenting factors quite a bit lower.
But this particular study is quite good. It was longitudinal, following parents and offspring at various ages during the offspring's childhood years (ages 6, 14, and 16), then following up in the offspring's young adulthood years (ages 22 and 33). Most importantly, the study carefully assessed parental psychological traits and symptoms, which in my opinion would help control for inherited traits confounding the results.
This article has some problems with lack of clarity in the writing. It was not exactly clear when the interviews were done (particularly the data from when the children were 6 years old). Also, in the tables, various items (such as "high praise and encouragement" in Table 2) are listed twice, with different numbers! I'm surprised that the writers and editors didn't address these things before publication.
In any case, the results show that various positive parental behaviours led to substantially reduced risk of future psychological problems in the offspring ("reduced aggregate offspring personality disorder symptoms levels" and "elevated aggregate offspring personality resiliency"). Here are a few examples (some of these things may seem like obvious truths -- but it is important to be reminded about just how important these are):
1) speaking kindly to child
2) being calm, not reactive with child
3) attention and dedication to child
4) raised child without reliance on punishment
5) lots of time spent with child
6) shared enjoyable activities with child
7) high affection toward child
8) good communication with child
9) high praise and encouragement
A few findings might be surprising to some. For example, "encouragement of offspring autonomy" from fathers actually was associated with a higher risk of offspring psychological problems.
Studies about parenting may seem to have limited relevance to those of us who are not parents, or who are not currently being parented. But I believe these findings can be generalized: in a psychodynamic sense, all relationships have at least a partial "parental" quality to them. We all also have a "parenting role" with ourselves! This role, and the behaviours or stance we take in this role, are undoubtedly coloured by the type of parenting we have experienced in our childhoods.
Findings of this type encourage us to change our "self-parenting":
1) Speak kindly to self!
2) Be calm and not reactive to self!
3) Be attentive and dedicated with yourself!
4) Be with yourself without reliance on punishment!
5) Spend lots of time with yourself!
6) Share enjoyable activities with yourself!
7) Have high affection toward self!
8) Communicate well with self!
9) And give self praise and encouragement!
10) If you are accustomed to "encourage autonomy in yourself" a lot, maybe you can give this one a rest.