Prior to Dianetics, psychiatry and psychology were adamant in their assertion that a person's IQ could not be changed. Their pronouncements were disproven in the face of study after study wherein persons showed dramatic increases in IQ after auditing. This test accurately measures the preclear's estimation of ten different personality traits. These rise markedly in auditing, reflecting the preclear's gains. Preclears report being calmer, more stable, more energetic and more outgoing as a direct result of auditing and scores on the OCA furnish corroborative data.
Aptitude tests are also a reliable indicator of auditing results.
Improvements in aptitude test scores correlate with a decrease in accident-proneness. Many other tests are available which test coordination and different perceptions such as vision, hearing, colorblindness, balance and so on, and these, too, improve as a result of auditing. Naturally, individual progress is variable since it is largely influenced by the preclear's dedication and the frequency of sessions. Therefore, clearly defined rates of improvement are impossible to establish. The Church makes no claims or guarantees of the gains someone will make in auditing.