rethinkingchildhood.com/no-fear/ Tim Gill blog worth a read for all the involountary 'be careful' mutterers. I am involved in the play sector, and right now the thrust of our work is getting parents to understand their children's own risk assessing ability. Can a toddler assess roadside safety? No, but that was not the point of original post.
Children that are allowed to play freely, with an absolute minimum of adult intervention have more confidence, better mental health, and are more able to deal with adversity as adults. This is what the previous poster meant by 'undermining the child's confidence.' If we show children that we don't trust them, how can they have confidence to trust themselves. The point about this being more of a problem for girls is prescient, and chimes with current feminist debates about why women are not as likely to put themselves forward for promotion etc.
Our play service has moved to a risk benefit analysis system, where our young children (4s and up) are encouraged with offerings of risky play opportunity (Trees to climb, mud slides, river play, tool use, fire, biking, racing carts etc) in anticipation of benefits to that child. This has been a difficult time for our service, and some playworkers have left - as they can't bear the unstructured nature of our playtime, disagree with the ethos, or just find it boring work - they are by and large quiet observers. (The best playworkers join in to a certain extent, modelling free play. We get some children who join up unable to play withput being told what to do.)
Our playworkers assess risk as the children play, but are trained in non intervention. The best of them leave it until it is unavoidable to stop play. For the most part, they never need to - as children have identified that they are not comfortable and change direction of play. Peer intervention is allowed and encouraged - and brings an interseting dynamic when young girls tell off big boys for showing off. Any adult interventions must be specific, such as 'do not touch that plant - it is poisonous' or 'you are very high in that tree, I can't see any branches that are strong enough for you higher up.' Playworkers do not say 'be careful' or 'watch out' or ask children to be 'safe.'
So perhaps that parent you see at the park 'not interested' is me, you should know that I am interested but that I am not looking because I can't bear to see my child twirling round the bar at the top of the slide, as I can't trust myself to not tell him to 'be careful.' I have assessed likelihood of accident as minimal, and am happy for him to carry on because of the joy and fun it is bringing, alongside the fact that he is testing himself and building confidence and a sense of capability. I am not angry at parents who do intervene, as I get where they are, I raised my oldest two children the same way. Of course, some parents may just be disinterested in general...interestingly their children will have the benefit of increased confidence in their own ability also - although neglect in other areas of their life can make this a toxic combination.
As ever, mumsnetters on both sides of this debate have entenched and are scoffing at each other. This forum would be a much nicer place if we all tried to practice a little more empathy, and judged a hell of a lot less.