The Hindu doctrine of karma, which has been on the rise in the West for over a century, teaches that the effects of bad deeds will make their way back to the originating individual. For those that are 130% convinced in the law, such as your author, its effects can often be seen very rapidly indeed. At other times it will be slower, but in truth it will always return. It has a basis in scientific rationalism. On the right here is a depiction of the "herd immunity" effect observed in public health policy. Because it lowers the chance of passing on a disease to another, vaccination lowers the basic reproductive number (or R-naught) of a pathogen below the crucial threshold of 1.0 required for an epidemic. Basically, if most - but not necessarily all - have the vaccine, a disease will not spread. It applies not only in a subtractive sense: the vaccine in this case being not amplifying unwholesome activities by replicating them, but in an additive sense too: always be prepared to proactively reward humanity indiscriminately if a good turn has been extended you. Not only need not everyone be vaccinated, it is not even necessary to follow the doctrine each and every single time: as long as the point prevalence (percentage of people who are willing to forgive at any given time) is high enough, peace will prevail.

On the left is an image I found on a WordPress blog entitled "thisisyourfather", self-reportedly someone explaining things about the world for his two young children.

See also