In the context of psychology, which of the following best defines a stimulus?

• A. A mental process involved in decision making
• B. An environmental event or change that elicits a response from an organism
• C. A learned behavior that is repeated over time
• D. A personality trait that influences social interactions

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the term 'stimulus' in psychology. A stimulus refers to any event or change in the environment that can influence an organism's behavior or physiological state.
2. Step 2: Recognize that a stimulus is external to the organism and acts as a trigger for a response, which can be behavioral or physiological.
3. Step 3: Differentiate a stimulus from internal processes such as mental decision-making or personality traits, which are not stimuli but rather internal states or characteristics.
4. Step 4: Note that learned behaviors and personality traits are outcomes or characteristics of an organism, not stimuli themselves.
5. Step 5: Conclude that the best definition of a stimulus is 'an environmental event or change that elicits a response from an organism,' as it captures the external cause-effect relationship fundamental to stimulus-response psychology.