"21.28 Are Only Children More Narcissistic? Researchers investigated whether the stereotype that only children are more narcissistic than children with siblings is true. As part of the study, the researchers compared the perceptions of people who were only children with those of people who had siblings. A representative panel of 556 people rated "a typical only child" using the the Narcissistic Admiration and Rivalry Questionnaire Short Scale test. Of the panel of 556 people, 105 were only children and 451 were people with siblings. Here are the summaries of the admiration scores for both groups:16 Group Sample Size Mean Standard Deviation Only child 105 3.50 1.03 Siblings 451 3.55 0.98 Is there evidence that the mean admiration score of a "typical only child" as rated by the population of only children is different from the mean admiration score of a "typical only child" rated by the population of people who have siblings?"