Why do you mean by the quality of population
Answers
ion quality is the overall level of certain desirable traits in a specific population. The members of a population do not contribute equally to the size of the next generation: The distribution of births, especially in low-fertility populations, varies markedly across the adult members. Because the data seem to show family resemblances across generations in these traits (the traits are familial whether they are transmitted genetically or socially), the question arises whether their overall level is going up or down as a result of this unequal distribution of births.
Increasing the Incidence of Desirable Traits
In most discussions of population quality the traits in question are health, intelligence, and what the scientist Sir Francis Galton, the coiner of the term eugenics, called "moral character"; this is frequently interpreted by modern psychologists as the personality traits of conscientiousness and altruism. However difficult it may be to define and assess such qualities in ways that command wide agreement, let alone consensus, it is obvious that people want to live in a society whose members are healthy, intelligent, conscientious, considerate, and civil toward others and prefer not to live in a society whose members are on the whole unhealthy, unintelligent, dishonest, lazy, and uncivil. The question, then, is how social policies in a specific population could be devised to increase the frequency of members with high amounts of the good traits and decrease the frequency of those with low amounts and whether such policies should even be sought.