According to Reed Larson, the battle against boredom involves developing an intrinsic motivation to direct effort toward a challenging goal, or

According to Daniel Levinson's social model of adult development, the "midlife crisis" involves

a. becoming less driven and more compassionate. b. conflict between generativity and stagnation. c. conflict between intimacy and self-absorption. d. moving away from family and assuming an adult role.

According to the article Deep Roots about fetal precursors of temperament, DiPietro et al. operationally defined temperament as:

(a) questionnaire responses from the mothers (b) actocardiograph readings (c) the number of times the infant turned toward its mother (d) the strength of the infant's social relationships