Which type of distribution has negative kurtosis and appears flatter with scores concentrated around the mean?

The correct answer is platykurtic. A distribution classified as platykurtic has negative kurtosis, which indicates that it is flatter than the normal distribution (mesokurtic) and has lighter tails. In this context, a platykurtic distribution demonstrates that the data points are more dispersed and the scores are more evenly spread out around the mean, leading to a flatter appearance.

In contrast, a leptokurtic distribution has positive kurtosis and is characterized by a sharp peak, indicating that data points are concentrated around the mean with heavier tails. A mesokurtic distribution, such as the normal distribution, has a kurtosis value that is neither excessively peaked nor flat but represents a moderate tailedness. Uniform distributions do not exhibit kurtosis in the traditional sense but rather present a constant probability across their range, leading to no concentration of scores around the mean.

Thus, the defining characteristic of platykurtic distributions is their negative kurtosis, which results in flatter shapes with scores spread out more extensively around the mean, making it the correct choice.