Because Mandisa always picked up her newborn daughter when she cried, her daughter is now a real crybaby. In this case, picking up the infant served as a(n) __ for crying. negative reinforcer positive reinforcer unconditioned stimulus conditioned stimulus

In this scenario, picking up the infant served as a **positive reinforcer** for crying. <br /><br />Here's the reasoning:<br /><br />- **Positive Reinforcer**: A positive reinforcer is a stimulus that, when presented after a behavior, increases the likelihood of that behavior occurring again in the future. In this case, Mandisa's daughter cries, and Mandisa picks her up. The act of being picked up is a pleasant experience for the daughter, which reinforces the crying behavior because it leads to a desirable outcome (being picked up).<br /><br />- **Negative Reinforcer**: A negative reinforcer is a stimulus that, when removed after a behavior, increases the likelihood of that behavior occurring again. This is not applicable here because the crying is not stopped by removing an unpleasant stimulus.<br /><br />- **Unconditioned Stimulus**: An unconditioned stimulus is something that naturally and automatically triggers a response without any prior learning. For example, food is an unconditioned stimulus that naturally triggers salivation in humans. In this case, the act of picking up the baby is not an unconditioned stimulus.<br /><br />- **Conditioned Stimulus**: A conditioned stimulus is a previously neutral stimulus that, after becoming associated with an unconditioned stimulus, comes to trigger a conditioned response. This is not applicable here because the act of picking up the baby is not a neutral stimulus that has become associated with another stimulus to trigger a response.<br /><br />Therefore, the correct answer is **positive reinforcer**.