It is important to have a positive attitude when obtaining a job because interviewees who are more positive tend to be more relaxed, more confident and more outgoing. These qualities make a candidate more desirable to potential employers.
According to the Journal of Managerial Psychology, interviewees who practiced positive mental imagery "had a higher performance and lower perceived stress levels" than participants who did not. By reducing stress, interviewees are more likely to ingratiate themselves to their potential employers. Without added stress, interviewees also appear less nervous and speak slower. These qualities contribute to a more personal interview, and make the candidate seem confident.
Psychological testing suggests that attitudes such as confidence and self-promotion have shown to have positive effects on the mindsets of both the interviewee and employer. In one such study performed in 2004, scientists found that the most successful employees were those who "proactively manage their environment." By confidently describing how they have controlled situations in the past (rather than be controlled by them), interviewees appear more positive and confident to their potential employers.
Confidence, calmness and preparedness are largely the result of a positive mindset in a job interview. If these traits are exhibited during an interview, they make a candidate more likely to be hired.