Developmental psychology studies changes throughout a person’s entire lifespan. This includes the physical, social, and cognitive developments and changes observed in a person. 

Stranger anxiety is a characteristic of secure attachment and usually begins around 8 months of age. It is more commonly described as a fear of strangers.

Audrey is currently in the formal operational stage, whereas Aaron is currently in the concrete operational stage. Children in the concrete operational stage such as Aaron fixate on the physical properties of objects and what they know to be true based on past experiences. In contrast, adolescents can think and reason more abstractly even when given hypothetical scenarios or specific rules to follow. So, when both Audrey and Aaron are asked about the glass, Audrey was able to follow the rule, but Aaron focused on the concrete validity of the rule; therefore, the children would respond in the following manner: “Audrey would say the glass broke, whereas Aaron would say the glass did not break.”

The ability to conserve physical properties first appears during middle childhood during the concrete operational stage (ages 7-11 approximately), not during the formal operational stage. Adolescents are first able to engage in hypothetical-deductive reasoning and propositional thought during the formal operational stage. Adolescents are also idealistic, which can be a gain or limitation cognitive ability. 

According to James Marcia's theory of identity statuses, Randall has made a commitment without exploring any additional options in terms of his field of study and career (i.e. identity foreclosure). Moratorium is when an individual is actively exploring an identity but has yet to commit. Achievement is when one has actively explored an identity and made a final decision. Diffusion is when one is indifferent and does not explore or commit to any one identity. 

Erikson's theory proposes that individuals have to resolve certain psychological conflicts across the lifespan, which in turn affects their personality development as well as their social and emotional well-being. During middle age, individuals must resolve the generativity vs. stagnation conflict. Individuals who resolve this conflict positively have children and grandchildren, give back to younger generations by mentoring or coaching in their careers, and feel a sense of achievement or accomplishment with passing down their knowledge. Those who resolve the conflict negatively do not interact with young adults and are still focused on themselves and what other people can do for them. 

Ego integrity vs. despair is the last stage of Erikson's psychosocial theory of the stages of development and corresponds to late adulthood. Individuals who have ego integrity reflect back on their lives and feel as if they have fulfilled their goals related to work and family. They often recognize that any challenges or problems they encountered were necessary for them to grow and make it to the point where they are currently in their lives. They often are not hopeless or regretful and typically do not fear death. 

During early adulthood, individuals who have established their identities (i.e. their career, gender, ethnic/racial, moral/religious, political, or sexuality preferences) are often easily able to commit to another person in a romantic relationship. Often times, they have developed secure attachment patterns with their parents/caregivers during infancy and toddlerhood, which impacts their future relationships and friendships. If they are self-absorbed,  then they are more likely to isolate themselves from other people. 

The evolutionary perspective suggests that women are more attracted to financial stability and ambition because it signals that their mate will protect, provide, and commit to the family. Since women have a limited reproductive capacity and have to carry children, they have to be more selective in who they choose. On the other hand, men are not limited by their reproductive capacity and are attracted to women who seem physically healthy and are able to bear and take care of children. 

Individuals at Level II in their moral reasoning focus on upholding laws to prevent anarchy and maintain good relationships with and approval from others around them. On the other hand, individuals at Level III in their moral reasoning understand if certain laws infringe on human rights, then in certain circumstances it may be appropriate to break a law (i.e., there are exceptions to a rule). This particular scenario focuses on revising the flawed law that is prohibiting Heinz' wife from living, which is why it is most related to maintaining social contracts with the law, while also acknowledging individual rights. Individuals who focus on universal principles reason beyond laws they consider unjust and adhere to maintaining the dignity of all people.