Prosocial behaviors are those intended to help other people. Behaviors that can be described as prosocial include feeling empathy（同感） and concern for others and behaving in ways to help or benefit other people. Prosocial behavior has long posed a challenge to social scientists seeking to understand why people engage in helping behaviors that are beneficial to others， but costly to the individual performing the action. Why would people do something that benefits someone else but offers no immediate benefit to the doer？ Psychologists suggest that there are a number of reasons why people engage in prosocial behavior. In many cases， such behaviors are fostered during childhood and adolescence as adults encourage children to share， act kindly， and help others. Prosocial behaviors are often seen as being compelled by a number of factors including egoistic reasons （doing things to improve one's self-image）， reciprocal benefits （doing something nice for someone so that they may one day return the favor）， and more altruistic reasons （performing actions purely out of empathy for another individual）. Characteristics of the situation can also have a powerful impact on whether or not people engage in prosocial actions. The bystander effect is one of the most notable examples of how the situation can impact helping behaviors. The bystander effect refers to the tendency for people to become less likely to assist a person indistress when there are a number of other people also present. For example， if you drop your purse and several items fall out on the ground， the likelihood that someone will stop and help you decreases if there are many other people present. This same sort of thing can happen in cases where someone is in serious danger， such as when someone is involved in a car accident. In some cases， witnesses might assume that since there are so many other present， someone else will have surely already called for help. Why do people help in some situations but not in others？ Experts have discovered a number of different situational variables that contribute to （and sometimes interfere with） prosocial behaviors. First， the more people that are present decreases the amount of personal responsibility people feel in a situation. People also tend to look to others for how to respond in such situations， particularly if the event contains some level of ambiguity. Fear of being judged by other members of the group also plays a role. People sometimes fear leaping to assistance， only to discover that their help was unwanted or unwarranted. In order to avoid being judged by other bystanders， people simply take no action. Experts have suggested that some key things must happen in order for a person to take action.（1）Prosocial behaviors are motivated for all the following reasons EXCEPT ____ .A. empathy for another individualB. instant benefits of helping othersC. parental influences in the early lifeD. the desire to better one's self-image（2）What does the underlined word "distress" in the fourth paragraph mean？ ____ A. peaceB. despairC. comfortD. trouble（3）Which situation can be described as the bystander effect？ ____ A. When hearing an injured lady crying for help， the neighbors didn't take action.B. Seeing an old man slipping on the icy road， many people volunteered to help.C. A woman was to give birth on the train and you were the only doctor there.D. On the scene of your colleague's traffic accident， you called the police for help（4）After the last paragraph， the most possible topic could be ____ .A. possible benefits of prosocial behaviorB. various reasons for prosocial behaviorC. situational influences on prosocial behaviorD. skills and knowledge to provide assistance