When perfection is the only goal then failure will be the most usual experience for a child and failure is a very unhappy thing indeed. (kidsmentalhealth.org)
Our investigation at the Columbus Psychiatric Institute and Hospital of Ohio State University has since been concerned not so much with the effects of stressful experience — which after all is the more usual experience of infants — as with the effects of the absence of such experience in infancy. (scientificamerican.com)
Along with usual experience points, you get Skill Points to level up particular abilities for each character. (playstationlifestyle.net)