The way in which you were treated as a child can impact your level of conscientiousness towards your health as an adult. The more you are treated to develop as a conscientious child, the less likely you are to abuse your health and vice versa.
The argument
Proponents of this position argue that the effects of childhood reach into adult life through the settled habits of character it forms, and that health is where those effects can be seen most plainly. On this account a person's childhood experiences shape them and therefore shape their beliefs; those beliefs in turn shape behaviour and conscientiousness — the disposition to plan, to follow through, and to take present obligations seriously. Because looking after one's own health consists very largely in behaviours of that kind, which pay off only over decades and only if sustained without supervision, a trait laid down in childhood becomes a standing determinant of how an adult treats their own body. The evidence advanced is longitudinal. In one study, children aged close to 10 years were assessed by their teachers on their levels of conscientiousness. When the same children were observed again as adults, at a mean age of 51, various health checks were conducted on them, and it was found that those who had been regarded as more conscientious had better global health than those who had not. Proponents stress what the design of such a study is meant to secure: the rating was made in childhood and the health measured some four decades later, so the ordering of events rules out an adult's health having produced the childhood rating, and the trait was identified by teachers rather than by the child or the family. On this reading the treatment a child receives, working through belief and then through conscientiousness, sets the pattern of health behaviour that person will follow as an adult, which is why proponents take childhood experiences to determine behaviour in later life. The inference rests on an observed association between an early rating and a much later outcome rather than on a directly demonstrated causal pathway.
Premises
Counter-arguments
Levels of conscientiousness are not set in stone throughout life. They can be developed as you transition through life. There are factors associated with the idea of being conscientious. When people engage in tasks that they find fit with their values, find enjoyable and important, the level of conscientiousness towards the task improves. A growing number of studies suggest that personality traits that are problematic to health can be improved, and this includes conscientiousness. By taking a bottom-up approach, and targeting the core personality traits, over time an individual is capable of altering these to generate healthier, more conscientious behaviour.
Rejecting the premises
[Rejecting P1] The chain from experiences to beliefs to behaviour and conscientiousness is asserted rather than evidenced, and conscientiousness has substantial temperamental and heritable components, so the premise assumes what the question asks. [Rejecting P2] The study links a childhood rating to adult health across four decades with no account of what happened in between — and as the counter notes, conscientiousness can be developed later in life, so the finding is consistent with influence rather than the determination this position claims.