Bad is stronger than good refers to the phenomenon that the psychological effects of bad things outweigh those of the good ones. Bad usually refers to situations that have unpleasant, negative, harmful, or undesirable outcomes for people, while good usually refers to situations that have pleasant, positive, beneficial, or desirable outcomes for people. Bad things have stronger effects than good things for virtually all dimensions of people’s lives, including their thoughts, their feelings, their behavior, and their relationships. Few topics in social psychology have approached the generality and validity of bad is stronger than good across such a broad range of human behavior.For the technical details, see this paper.
Nearly all academic child-care experts advocates something called positive parenting. But is there any research to show that it gives better outcomes? Not really.
Good acts just don't make that much of an impression on a child. Kids from families with model positive parenting parents don't turn out much different from average parents who do not do anything unusual.
Sure, some bad acts are harmful, so an absence of bad acts is beneficial in that sense. Any benefit to positive parenting is probability entirely due to avoid certain bad acts.
The so-called bad acts are not necessarily harmful. For example, overcoming adversity can be character building. If you look at the lives of great men, many have overcome all sorts of adversities that would be considered bad acts. These bad acts were probably more influential than the good acts.