Uh, actually, the science of successful parenting shows that children who are high in self-control are more likely to come from homes with house rules. (Lengua, Honorado, & Bush, 2007; Schroeder & Kelley, 2010)
But let's set that aside for the moment. What do they allege that the science of successful parenting suggest? Apparently "psychologists find that children can-learn self control without externally imposed pressure."
Well, in one sense that's surely true: kids ability to regulate their emotions, delay gratification and engage in other acts of self-control does improve as they get older, whether parents work on that skill or not.
But merely waiting is not what the authors have in mind, of course. But there's not much reason to think that the strategies they suggest will be effective.
1) help the child find a hobby he or she is really excited about
2) encourage the child to engage in imaginative play
3) learn a second language (which does yield cognitive benefits, but not self-control of the sort alluded to in the rest of the article)
4) encourage aerobic exercise
It's hard to take these suggestions seriously because the descriptions are incomplete. Imaginative play does improve self-control, but the way in which the play is orchestrated can't really be left to chance. The successful "Tools of the Mind" curriculum uses lots of imaginative play, but the drama is not left utterly up to kids. It requires a skillful teacher (and a set of ground rules as to how the drama is to be carried out) for the strategy to work.
A hobby might help self control if the child is (as the authors say) passionate about it, and so learn that hard work is necessary for a desired payoff. But again, you're sort of leaving a lot to chance if you hope that your child will develop a hobby consonant with that, and will actually stick with it. (I'm reminded of the 13-year-old son of a friend, who calmly told his mother "Mom, don't you get it? Watching TV is my hobby. It's what I do.")
I'm not arguing for "strict parenting." I'm arguing for home factors that the science of parenting actually shows is associated with self-control in kids: parental warmth, and a predictable, organized home environment,
I wrote an article summarizing self-control which you can find here.
Liliana J. Lengua, Elizabeth Honorado, and Nicole R. Bush, “Contextual Risk and Parenting as Predictors of Effortful Control and Social Competence in Preschool Children,” Journal of Applied Developmental Psychology 28, no. 1 (2007): 40–55.
Valarie Schroeder and Michelle L. Kelley, “Family Environment and Parent-Child Relationships as Related to Executive Functioning in Children,” Early Child Development and Care 180, no. 10 (2010): 1285–1298.