Final answer:
The reason people are less willing to help someone in distress when others are present is because of the bystander effect and diffusion of responsibility.
Step-by-step explanation:
The reason people are less willing to help someone in distress when others are present is because of the bystander effect and diffusion of responsibility. The bystander effect is a situation in which people are less likely to interfere during an emergency or when a social norm is being violated if there are others around. This is because they feel less responsible due to the presence of other bystanders. Diffusion of responsibility refers to the tendency for no one in a group to help because the responsibility is spread throughout the group.