The Hood Mysticism Scale: does the presence of a neutral response-item affect response style

The widely used Hood Mysticism Scale (1975) was administered to one of two groups of college students in its original version and a modified version without the option of responding with "?" to an item. Scoring of the scale assigns an intermediate value to the "?" response, suggesting this response implies a meaning on the item somewhere between "probably true" and "probably not true." Omitting this response option requires respondents to make a forced-choice answer, either to agree or to disagree with a statement and eliminates the middle ground. It was hypothesized that, if the response reflects a neutral attitude, then randomly selected groups administered the scale with or without the option should show no difference in overall means. An intact group of 23 advanced psychology students achieved a mean of 114.4 (SD = 20.4) on the original mysticism scale, while 25 advanced psychology students in a second intact group had a mean of 113.3 (SD = 17.1) on the modified version. This difference was not significant and supported the hypothesis that the scales were equivalent. Advantages of the modification and implications for interpretation of the "?" response are discussed.