114 Ho 7: Introverts and extraverts will not differ on the Health Locus of Control scale. In the gastric bypass group (Table 4-55) and the hand surgery group (Table 4-56) introverts and extraverts did not differ on the Health Locus of Control Scale. Significant differences (p < .05) between introverts and extraverts were found on the health locus of control scale in the hand rehab group (Table 4-57). Therefore, the null hypothesis is rejected for the hand rehab. group. The SRTT analysis did not show significant overrepresentations or underrepresentations of introverts or extraverts on the Health Locus of Control scale. Summaries of the SRTTs are in Tables 4-58 and 4-59. The complete SRTTs are in Appendix E. Table 4-55 t Test for Differences Between the Bipolar Scales of the MBTI on the HLC Scale (Bypass Group) Scale n % Mean SD t E 18 56.25 32.94 9.6 0.157 I 14 43.75 34.14 6.7 S 23 71.88 35.69 5.4 6.864*** N 9 28.13 27.77 11.8 T 10 31.25 36.70 7.2 2.249* F 22 68.75 32.00 8.5 J 14 43.75 34.78 4.7 0.607 P 18 56.25 32.44 10.3 *P < .05. **P < .01. ***D < .001.