Members of a group will often feel less inclined to do something about a situation; the larger the group, the less an individual will feel a sense of responsibility to take charge. This is called a "diffusion of responsibility" and is thought to be responsible for the "bystander effect", which describes the unwillingness to offer help if others are present and are also not offering help. The distinction is small, but important.

Even though many participants felt that they were causing a great deal of pain to the person that they were shocking, they continued to use higher voltage simply because the test administrater told them to. This experiment demonstrated the power that presumed authority has over people's actions and decisions. 

The bystander effect suggests that the more people who witness someone in distress, the less likely someone is to intervene. Diffusion of responsibility refers to the phenomenon such that when there are multiple people present, each individual feels less of a responsibility for the situation. Social influence refers to the effect that seeing other people not acting causes you to be less likely to act.

Group polarization occurs when a group makes a more extreme decision than its individual members would have made if acting on their own. 

Because joining a cult often requires a dramatic shift in one's behavior and philosophies, people who are reluctant to disrupt their own status quo are less likely to join a cult, no matter how enticing their recruiters' promises may be.

Each factor listed introduces the possibility of harm to a potential actor, be it a minor inconvenience or a greater physical threat, making them more reluctant to aid someone else.

Instrumental aggression is an act of aggression that is designed to meet a particular goal. This act could be made at the individual or societal level. A good example would be particular wars in which countries fought over food, water, or other resources needed or wanted to maintain their society. This is different from hostile aggression, which could be random with no specific cause or end goal. 

Solomon Asch is most well-known for his social psychology studies on conformity. Individuals are most likely to conform when they are in a group. Social normative refers to the influence other people have on an individual that leads to conformity, driven by a desire to fit in. If an individual has not yet voiced their opinions, they are also more likely to conform to a group's view. Outside influences such as these have a major impact on conformity.

Deindividuation is the process whereby individuals show a loss of restraint and individuality due to their being in a group. Having personal ties to a victimized party would decrease deindividuation, while all of the other answer choices facilitate "losing" oneself to a larger group identity. 

Social loafing is a phenomenon whereby some people exert less effort when working in groups as opposed to when they are working individually. Obviously, the option describing Johnny doing exactly that is the best answer.