559 undergraduates answered one number using the numbers 0-9 without special instructions. Histograms of each response were analyzed using a log-liner model and chi-square methods. Distribution biases were studied with the choice of preference number. The first preference distribution of numbers showed that the most frequent number was three. Five and seven were also chosen frequently. The least frequent number was nine. All characteristic numbers in appearance were odd and almost chance level frequency were even without zero. This phenomenon was very steady state in undergraduates. The reason of this phenomenon was collected from subjects. The most frequent answer of reasons was position preference of sequence numbers. A pseudo scientific conviction might be shaped from the information of communication. It was so called superstitious behavior. In human subjects random response number was rare generated. An instruction for the prediction of the least number in next response forced the preference changing. This result showed the distribution of numbers were near chance level frequency. It suggests that the human being might have the tendency of straight response bias.