There have been online courses in the US and UK for a number of years - but there has been a recent surge of interest as self-study courses have been put online by some of the world's most famous institutions.
Meanwhile, advertisers have released their own study arguing that self-regulation, as opposed to government-imposed restraints, are sufficient to combat dubious food and health claims in advertising.
Some grow up in safe, nurturing environments, and although they react swiftly to challenges, they have more self-control and calm down quickly, the study says.